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In this study, BF2 complexes of pyridyl‐isoindoline‐1‐ones (BPIO) has been firstly designed and investigated as an excellent corrosion inhibitor for the mild steel in 1 M HCl. The corrosion protection properties of BPIO were studied by using a series of experiments. The results indicated BPIO has excellent inhibition performance, and inhibition efficiency of BPIO reached up to 96.6%. The effects of immersion temperature and time were investigated by weight loss experiments to evaluate the stability of adsorbed BPIO film in protecting steel surface. Based on potentiodynamic polarization studies, BPIO acted as one mixed‐type corrosion inhibitor with predominant anodic effectiveness, and its adsorption on the mild steel follows the Langmuir adsorption isotherm. The values of ΔGads suggested the adsorption of BPIO on the mild steel surface was through a combination of chemisorption and physisorption. The adsorption of BPIO molecules on the steel surface was further identified by the techniques of scanning electron microscopy (SEM) and X‐ray photoelectron spectroscopy (XPS). The quantum chemical calculations based on density functional theory (DFT) and molecular dynamics (MD) simulations were used to optimize the BPIO molecular structure and investigate the inhibitive properties on the theoretical level, which agreed well with the experimental results. Besides, BPIO has been used for the development of water soluble metal antirusting agent. [ABSTRACT FROM AUTHOR]

This work reports the magnetic index of aromaticity of cyclophosphazene (c$$ c $$‐P3$$ {}_3 $$N3$$ {}_3 $$H6$$ {}_6 $$) and their halogenated cyclic derivatives: c$$ c $$‐P3$$ {}_3 $$N3$$ {}_3 $$F6$$ {}_6 $$, c$$ c $$‐P3$$ {}_3 $$N3$$ {}_3 $$Cl6$$ {}_6 $$, c$$ c $$‐P3$$ {}_3 $$N3$$ {}_3 $$Br6$$ {}_6 $$, c$$ c $$‐P3$$ {}_3 $$N3$$ {}_3 $$I6$$ {}_6 $$, c$$ c $$‐P3$$ {}_3 $$N3$$ {}_3 $$At6$$ {}_6 $$ and c$$ c $$‐P3$$ {}_3 $$N3$$ {}_3 $$Ts6$$ {}_6 $$. This index, also known as ring‐current strength, is calculated by numerical integration of the magnetically‐induced current density vector field which is generated by a perturbing external magnetic field. Due to the presence of heavy X=Br,I,At$$ \mathrm{X}=\mathrm{Br},\mathrm{I},\mathrm{At} $$ atoms in c$$ c $$‐P3$$ {}_3 $$N3$$ {}_3 $$X6$$ {}_6 $$, important relativistic were expected. Accordingly, all‐electron density functional theory (DFT) calculations were carried out using the four‐component Dirac‐Coulomb (DC) Hamiltonian, including scalar and spin‐orbit relativistic effects. The values were also compared with the corresponding spin‐free (scalar relativistic) ones. [ABSTRACT FROM AUTHOR]

The kinetic and mechanistic studies for the reaction of hydroxyl radical with two quinoline based herbicides, namely, quinclorac and quinmerac has been performed using various computational methods in aqueous media. Geometry optimizations were performed using Density Functional Theory (DFT) methods including water as the solvent. Local reactivity parameters of these herbicides towards the •OH radical are predicted using condensed Fukui function. Single point energies of various species were calculated using double hybrid method, namely, B2PLYP–D for better accuracy. The pKa values for these acid based herbicides allow them to exist in deprotonated form in aqueous condition. Hence, the calculations are also performed for the deprotonated or the anionic form apart from the neutral species. Individual rate coefficients for •OH radical addition reaction with each carbon atoms were evaluated using conventional transition state theory using one–dimensional tunneling corrections. The solvent effect on reaction is implemented through Collins–Kimball formulations. Both the approaches, namely, the Fukui index and individual rate constant determination confirms that the most reactive site for the •OH radical addition in these two herbicide is the carbon atom attached to the COOH group. The total rate constant for the •OH radical reaction with both neutral and anionic forms of these two herbicides are relatively high and equal to its diffusion‐limit value. Evaluation of the ecotoxicities of the parent herbicides and their OH adducts is estimated using the structure–activity relationship concept. [ABSTRACT FROM AUTHOR]

Using ab‐initio DFT based simulations, the hydrogen storage capacity of transition metal (TM = Ni, Pd) decorated doped germanium carbide nanotubes (GeCNTs) with heteroatoms (B, N, Ga, and As) has been examined. The study reveals that each Ni atom bonded on GeCB, GeCN, GeCGa, and GeCAs can attach at the most of 3H2, 2H2, 4H2, and 5H2 molecules with an average binding energy of −.36, −.40, −.32, and −.37 eV/H2, respectively. When doped GeCNTs are fully decorated with Ni atoms, their gravimetric hydrogen storage capacities are around 4.05, 2.73, 5.38, and 6.57 wt%, respectively. The desorption temperature of the systems is 460, 511, 404, and 473 K, respectively. When doped GeCNTs are fully decorated with Pd atoms, their gravimetric hydrogen storage capacities are around 2.07, 3.07, 4.05, and 3.07 wt%, respectively. These findings demonstrate that doped‐GeC adorned with Pd does not satisfy US DOE hydrogen storage requirements. The molecular dynamic (MD) calculations are utilized to examine the stability of the considered structures. The results demonstrate that Ni‐adorned GeCAs are a suitable material for hydrogen storage, which will motivate scientists to fabricate GeCAs‐based fuel cell devices. [ABSTRACT FROM AUTHOR]

A comprehensive density functional theory (DFT) investigation of the catalytic oxidation of NO to NO2 on neutral and charged [Pt2]0,± dimers has been considered employing M06L/def2TZVP level of theory. Single as well as co‐adsorption energies of NO and O2 molecules suggest that the traditional Langmuir Hinshelwood (LH) mechanism and less explored termolecular Eley–Rideal (TER) and termolecular Langmuir Hinshelwood (TLH) mechanisms, are suitable for a full catalytic reaction pathway in which two NO molecules are converted to two NO2 molecules, initiated by an activated O2 molecule. Activation barrier reveals that the TER mechanism is found to be more reliable in converting two NO molecules into two NO2 molecules on [Pt2]¯ dimer. In addition to shedding light on the intrinsic characteristics of Pt2 dimers, the study will serve as a benchmark for investigating the oxidation process of NO to NO2 utilizing models of termolecular chemical processes. [ABSTRACT FROM AUTHOR]

There is still a lack of research on the effect of the S and Fe vacancy on the adsorption mechanism of peroxide (H2O2) on the pyrite surface. In this work, the adsorption of H2O2 molecules on the perfect and defective pyrite surface is simulated based on density functional theory (DFT). The results indicated that the adsorption energy of H2O2 molecules on the S‐vacancy surface is relatively lower than that on the perfect surface and dissociative adsorption entirely occurs, while the adsorption behavior of H2O2 molecules on the S‐rich pyrite surface has not occurred. When the H2O2 molecules are adsorbed on the Fe‐rich pyrite surface, two products appear, one with two OH− species and the other with an H2O molecule and an O atom. The analysis of the transition state (TS) found that the dissociation of the H2O2 molecule producing two OH− species that bond with two Fe atoms is more likely to occur. In addition, based on the coordination chemistry, it is demonstrated that Fe atoms are more reactive around an S vacancy than on a perfect surface. [ABSTRACT FROM AUTHOR]

To delve into the microscopic property variations of the ConMoP(n = 1 ~ 5) cluster, this study employs density functional theory at the B3LYP/def2‐TZVP quantum chemistry level. The paper conducts a comprehensive theoretical analysis of the clusters, examining parameters such as bond lengths, bond angles, electronic localization function (ELF), interaction region indicator function (IRI), independent gradient model based on the Hirshfeld partition, deformation density, electronic space range, chemical hardness and softness, polarizability, and dipole moment. The optimization process reveals 16 stable configurations for the ConMoP(n = 1 ~ 5) cluster, predominantly taking on a steric form. As the cluster size increases, the electronic delocalization of Co atoms intensifies, while the electronic properties of Mo atoms remain relatively stable. Notably, P atoms maintain a high degree of electronic delocalization. The interatomic forces within the clusters predominantly exhibit covalent bonding, with no evident repulsive effects observed between atoms. The bonding between metal atoms in the clusters leans toward a preference for covalent interaction. The degree of dispersion in the clusters increases with their growth, particularly evident in configuration 5‐a, which displays a broader spatial distribution. Configuration 3‐a demonstrates the most favorable activity, showcasing a relatively stable structure. Overall, configuration 3‐a emerges as a focal point for catalytic reactions. This article provides a more comprehensive analysis of the ConMoP(n = 1 ~ 5) cluster, yielding diverse results and enhancing the theoretical understanding of this cluster. [ABSTRACT FROM AUTHOR]

To efficiently desorb H2, pure Mgn (n = 4–8) clusters were chosen for the hydrogen evolution reaction with H2O. At the PBE0/def2‐TZVP level and the PBE0‐D3/def2‐TZVP level, the lowest energy structures of Mgn (n = 4–8) clusters and the most stable structures of Mgn@H2O (n = 4–8) complexes were searched in the local region. The transition state was predicted, and then the hydrogen evolution reaction channel was obtained by using the intrinsic reaction coordinate (IRC) to confirm the transition state. To better analyze the hydrogen reaction mechanism, the character of Mgn@H2O (n = 4–8) complexes and MgnO (n = 4–8) clusters, as well as the atomic charge change trend, were investigated using interaction region indicator function analysis (IRI) and natural population analysis (NPA). The reaction effect of Mg4 cluster and H2O is the worst. The energy barrier does, however, progressively lower as the cluster atom count rises, improving the reaction effect. [ABSTRACT FROM AUTHOR]

This investigation employed computational methodologies to assess the therapeutic potential of derivatives (1–16) of pyridoxal isonicotinoyl hydrazone (PIH) as potential treatments for tuberculosis. Various computational techniques, including molecular dynamics simulation, molecular docking, density functional theory, and global chemical descriptors, were employed to analyze the interactions between the ligands and target proteins. Docking results indicated that ligands 6, 7, 8, and rifampin exhibited binding affinities of −8.4, −7.4, −9.2, and − 7.2 kcal mol−1, respectively, against mycobacterium tuberculosis enoyl acyl carrier protein reductase (INHA), with ligand 8 demonstrating superior inhibition. Molecular dynamics (MD) simulations were utilized to assess the stability of protein‐ligand interactions. Remarkably, the Root Mean Square Deviation (RMSD) of the INHA‐ligand 8 complex remained minimal, with peak values at.40,.56,.37, and.50 nm at temperatures of 300, 305, 310, and 320 K, respectively. This suggests superior stability compared to the reference drug rifampin and INHA complex, which exhibited an RMSD range of.2 to.8 nm at 300 K. Furthermore, analysis using Frontier Molecular Orbital (FMO) revealed that the Egap value of ligand 8 (4.407 eV) is lower than all the reference drugs except rifampin. This comprehensive theoretical analysis positions ligand 8 as a promising candidate for anti‐tuberculosis drug development, underscoring the need for further exploration through in vitro and in vivo studies. [ABSTRACT FROM AUTHOR]

Making products that are affordable, environmentally friendly, and energy‐efficient is the main objective of modern production. The objective of this research is to discover compounds that meet these parameters. The full‐potential, linearized augmented plane wave program (FP LAPW) offered by Wien2K was used to examine the structural, optical, electrical, and transport aspects of SrCaGe and SrCaSn Half‐Heusler (HHs) compounds. Generalized gradient approximation (GGA) was considered for the structural optimization and computation of elastic properties signifies inherent ductility and mechanical stability of the examined SrCaGe and SrCaSn compounds. Additionally, both materials were found to possess a direct bandgap and exhibit semiconducting behavior. The bandgap magnitudes obtained utilizing the modified Becke‐Johnson (mBJ) approximation are 0.78 and 0.52 eV for SrCaGe and SrCaSn, respectively. According to their optical characteristics, SrCaGe and SrCaSn show potential for application in optoelectronic components. Furthermore, the transport properties are evaluated by BoltzTrap program, revealing that both SrCaGe and SrCaSn exhibit figures of merit (ZT) values nearly equal to one at room temperature. This suggests their potential use in creating thermoelectric devices with highly efficient performance. The simulation study demonstrates the promising attributes of SrCaGe and SrCaSn HHs materials, positioning them as viable candidates for various applications, aligned with the goals of sustainable and efficient manufacturing. [ABSTRACT FROM AUTHOR]

Driven by the goal of establishing a fossil‐fuel‐free and nuclear‐power‐free economy based on renewable energy, metal‐air batteries are regarded as promising energy conversion and storage devices. Developing efficient oxygen reduction reaction (ORR)/oxygen evolution reaction (OER) bifunctional electrocatalysts for the air electrode of metal‐air batteries is becoming increasingly important. In this work, 36 transition metal (TM) single‐atom catalysts are designed based on MXenes Ti2CT2 with different surface terminal atoms (T = O, S, Cl), and their ORR/OER catalytic activity and stability are evaluated by the density functional theory. Ni@Ti2CO2, Pd@Ti2CS2, and Co@Ti2CCl2 are found to exhibit good catalytic activity with ORR/OER overpotentials of.54 V/.62 V,.59 V/.29 V,.44 V/.40 V. The aggregation behavior of three catalysts is estimated by comparing the average binding energy of one, two, three, and four TM atoms anchored on Ti2CT2. This work cannot only provide a theoretical guide to develop bifunctional single‐atom catalysts, but also help us understand the effect of terminal atoms on the electronic structures and catalytic activity of TM@Ti2CT2. [ABSTRACT FROM AUTHOR]

This research work investigates the structural, electronic, optical, and thermoelectric characteristics of VFeZ (Z = N and P) half‐Heusler compounds. The study employs the full‐potential linearized augmented plane wave (FP‐LAPW) method integrated into the WIEN2K algorithm, serving as the underpinning framework for density functional theory (DFT) analysis. In the study, we use the PBE generalized gradient approximation (PBE‐GGA) to identify numerous parameters associated with structural and elastic properties. Lattice parameter results are in agreement with previous outcomes. Moreover, computed elastic parameters satisfy the criterion for stability. In the cubic structure VFeZ (Z = N and P) is ductile, to enhance the computations of electronic characteristics, Tran and Blaha's modified Becke‐Johnson potential (TB‐mBJ) is used. Our simulations demonstrate that the materials exhibit semiconductor behavior, with a direct band gap for VFeZ (Z = N and P). Strong UV absorption is found via optical experiments suggest compounds are suitable for optical application. Furthermore, study of the thermoelectric properties suggests its application in the thermoelectric generators. [ABSTRACT FROM AUTHOR]

The current study reports tailoring the electronic donor structures of organic dyes to modify their optical and nonlinear optical (NLO) response properties. Five (5) tri‐phenyl amine (TPA) based Donor‐π‐Acceptor (D‐π‐A) organic dyes with the codes ICAA1, ICAA2, ICAA3, ICAA4, and ICAA5 were designed and investigated for their optical and NLO properties using quantum chemical methods. Optical and NLO properties of these dyes were studied by CAM‐B3LYP method and 6‐311G* basis set. The focus has been on the impact of adding secondary donors and shifting their substitutions at ortho (o), meta (m) and para (p) positions. Among all designed compounds, ICAA4 showed the highest amplitude of average third‐order NLO polarizability <γ>, which is calculated to be 1316 × 10−36 esu. Time‐dependent Density Functional Theory (TD‐DFT) method was used to determine how a change in the position of the donor affected the excitation energy (Eg) and NLO response properties. The findings showed that changing the position of the secondary donor results in a red shift among absorption spectra as well as the increase in their NLO responses. Complete process of intramolecular charge transfer (ICT) has been investigated in terms of different optical parameters such as frontier molecular orbitals (FMOs), molecular electrostatic potentials (MEPs), transition density matrix (TDMs), density of states (DOS), electron density difference (EDD), and natural bond orbital (NBO) analysis. Our calculations for study of ICT process indicate that p‐position of methoxy group performs better among all other positions and even it has better NLO response properties than the compound with three collective methoxy groups. The calculated Voc values of all designed molecules range from 1.09 to 1.30, all of them are positive while their ΔGinject is found to be in the range of −0.87 to −1.79 eV indicating their decent potential for photovoltaic applications. The studied optical, NLO and photovoltaic parameters illustrated that ICAA1 to ICAA5 are appropriate molecules not only for NLO applications but also for efficient photovoltaic purposes. [ABSTRACT FROM AUTHOR]

Quantum dots have many potential applications in opto‐electronics, energy storage, catalysis, and medical diagnostics, silicon carbide quantum dots could be very attractive for many biological and technological applications due to their chemical inertness and biocompatibility, however, there are seldom theoretical studies that could boost the development of these applications. In this work, the electronic properties of hydrogenated spherical‐like SiC quantum dots with C‐rich and Si‐rich compositions are investigated using density functional theory calculations. The quantum dots are modeled by removing atoms outside a sphere from an otherwise perfect SiC crystal, the surface dangling bonds are passivated with H atoms. Our results exhibit that the electronic properties of the SiC‐QD are strongly influenced by their composition and diameter size. The energy gap is always higher than that of the crystalline SiC, making these SiC QD's suitable for applications at harsh temperatures. The density of states and the energy levels show that the Si‐rich quantum dots had a higher density of states near the conduction band minimum, which indicates better conductivity. These results could be used to tune the electronicproperties of SiC quantum dots for optoelectronic applications. [ABSTRACT FROM AUTHOR]

The structures and properties of seven substituted dithiophosphate (DTP) collectors containing three types of functional groups (O2PS2, C2PS2, and N2PS2) were studied using density functional theory. The collectors studied were dibutyl dithiophosphate (DNBDTP), diisobutyl dithiophosphate (DIBDTP), dibutoxyethyl dithiophosphate (DBOEDTP), xylenol dithiophosphate (DMPDTP), diisobutyl dithiohypophosphite (3418A), diphenylamine dithiophosphate (DTADTP), and dicyclohexylamine dithiophosphate (DCADTP). The structural analysis showed that the PS bond lengths in the C2PS2 and N2PS2 types are longer than those in the O2PS2 type, indicating that the strength of the PS bond is weaker in the former two. The frontier molecular orbital studies showed that the energy differences between the highest occupied molecular orbitals (HOMO) of 3418A (C2PS2 type) and DCADTP (N2PS2 type) and the lowest unoccupied molecular orbital (LUMO) of galena are significantly lower than those of the other collectors, suggesting that C2PS2 type and N2PS2 type with cyclohexane could enhance the interaction with galena. Using the Fukui function to calculate the nucleophilicity and electrophilicity of the sulfur atom indicated that the S atom exhibits nucleophilicity, especially in DMPDTP and DTADTP, which contain benzene rings, and the S atom exhibits strong nucleophilicity without electrophilicity. However, due to the lack of contribution from S atoms to the LUMO orbitals, the S atoms in these two compounds are not participate in any LUMO reactions. The adsorption results demonstrated that 3418A (C2PS2 type) and DCADTP (N2PS2 type) exhibit the strongest adsorption on Pb2+ ions, while DMPDTP (C2PS2 type) and DTADTP (O2PS2 type) which contain benzene rings, as well as DBOEDTP (C2PS2 type) which does not contain a benzene ring, exhibit weaker interaction compared to the other compounds. These are consistent with the results of the frontier molecular orbital and electrophilic nucleophilicity calculations. [ABSTRACT FROM AUTHOR]

The substitution of heteroatoms and the expansion of π‐conjugated units have significant effects on the photoelectric properties of polycyclic aromatic hydrocarbons (PAHs). In this study, based on the experimental molecule PBC, 10 acene derivatives containing the pyrrole group were designed by three strategies: (1) changing the connection position of the pyrrole group, (2) exchanging the position of the N atom, and (3) increasing the length of the π‐linker. Density functional theory (DFT) was used to optimize the molecular geometric structure. Time‐dependent density functional theory (TD‐DFT) was used to calculate the relevant parameters of the excited states. The results show that both of the pyrrole group and the N atom in the para‐position, and the addition of the π‐linker can reduce the energy gap, cause redshift of the linear absorption peak, and increase the two photon absorption (TPA) cross‐section. The analyses of the charge density difference (CDD) and the charge‐transfer matrix (CTM) proved that the electron transfer is mainly concentrated in the π‐linker. Moreover, the participation of the multi‐ring skeleton on both sides decreases gradually with the increase of the length of the π‐linker. The length of the π‐linker changes the dominant transition channel and intramolecular charge‐transfer (ICT) characteristics of TPA, thus affecting the transition dipole moments and nonlinear absorption properties. The second hyperpolarizability of the designed molecule PBI5‐p5 is also significantly superior to that of similar materials reported. It is expected that the above molecular design strategies and comprehensive analysis of nonlinear optical (NLO) properties could provide theoretical support for the research on acene derivatives. [ABSTRACT FROM AUTHOR]

Hydrogen bonds are of vital importance in the formation and functioning of organic molecules; their characterization with theoretical tools is a task of interest to the scientific community. Commonly, the electron density at the bond critical point is used to characterize bonds. Generally this task is carried out with ab‐initio methods. In this study, the PM7 semi‐empirical approach is used to evaluate the quality of the electron density at the hydrogen bond critical points (HBCPs). The research takes into account dimers, nucleobases and alpha‐helices bonded by hydrogen bonds: OH⋯O$$ OH\cdots \mathbf{O} $$, OH⋯N$$ OH\cdots \mathbf{N} $$, NH⋯O$$ NH\cdots \mathbf{O} $$, NH⋯N$$ NH\cdots \mathbf{N} $$, CH⋯O$$ CH\cdots \mathbf{O} $$, and CH⋯N$$ CH\cdots \mathbf{N} $$. The results are compared with second‐order Møller–Plesset and density functional theory. The findings demonstrate that PM7 is a reliable alternative for explaining the electron density trends at the HBCPs. [ABSTRACT FROM AUTHOR]

The structural, electronic, and thermodynamical properties of Cn(N3)m (n = 1–7) (m = 4, 6) organic azides have been investigated using Density Functional Calculations. The ground state structures of organic azides were compared with CnHm (n = 1–7) (m = 4, 6) cumulenes which shows their higher relative stability. The stability and reactivity of organic azides were analyzed by calculating the HOMO‐LUMO gap, binding energies, and harmonic frequencies of the azides. The binding energy and formation energy of Cn(N3)m (n = 1–7) (m = 4, 6) organic azides suggest their energetic stability. The structural analysis of the azide group in Cn(N3)m (n = 1–7) (m = 4, 6) organic azide shows a tendency to stabilize at a maximum separation between functional azide groups. Ionization potential, electron affinities, and global hardness have been computed for Cn(N3)m (n = 1–7) (m = 4, 6) organic azides and the odd–even alternation rule was observed. The molecular dynamic simulation performed at 300 K for 1 fs confirms organic azide's structural stability at room temperature, except for C4(N3)4, and the members of their family can be synthesized. [ABSTRACT FROM AUTHOR]

The 2D network having porphyrin like internal core are well established in literature due to their remarkable molecular tunability, photophysical and optoelectronics properties. Therefore, in the quest to attain the high performance nonlinear optical (NLO) response we have designed single Benzo‐bisimidazole (BIZ) unit which has porphyrin like motif and expanded it strategically in such a way that it forms cage and further it convert into 2D nanosheet. Density functional theory (DFT), sum‐over‐state models and time dependent‐DFT (TD‐DFT) simulation were performed for geometric and electronic properties calculation. Expanding the BIZ plays a pivotal role in enhancement of the first static hyperpolarizability (βtot) from 205.65 to 13754.59 au. Further, alkali metals substitution leads to gigantic enhancement of βtot value from 2200.17 to 636673.60 au which is enormously higher than that of recently reported porphyrin derivative (47950 au). Calculated results revealed that the gap between highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) become narrow down from 6.28 eV (1) to 1.70 eV (6). It is to note that the designed molecules exhibit red shift of absorption. Further, density of states (DOS), and transition density matrix (TDM) analysis have also performed to explore the charge transfer and structure property relationship. [ABSTRACT FROM AUTHOR]

Halide base perovskite LiCdX3 (X = F, Cl) is tested by CASTEP (Cambridge Serial Total Energy Package) based on density function theory (DFT). The presented discussion is to explore the structural, electronic, and optical properties of LiCdX3 (X = F, Cl). The calculated values of the lattice parameter are found to be 3.8 Å and 5.27 Å of LiCdF3 and LiCdCl3 respectively. The ideal structure of LiCdX3 (X = F, Cl) is cubic and dynamically stable. Electronic properties show that materials are semiconductors. The results from band structure are further evaluated by the total and partial density of states. The partial and total density of states confirms the degree of localization of electrons. In optical properties, the highest absorption coefficient is observed in LiCdCl3. The material is half metallic and has a narrow indirect band gap which may be used in photovoltaic applications. [ABSTRACT FROM AUTHOR]

In this paper, we study and discuss the structural, and electronic properties of the RbXF3 (X = Co, Mn, V or Fe) Perovskite Materials using the Density Functional Theory (DFT). Also, the origin of both semi‐conductor (SM) and half‐metallic (HM) characters have been outlined. The density functional theory (DFT) has been applied to illustrate the physical properties of the RbXF3 (X = Co, Mn, Fe or V) perovskite materials. The generalized gradient approximation introduced by Perdew–Burke and Ernzerhof (GGA‐PBE) with Hubbard correction has been used for modeling the physical properties of the RbXF3 (X = Co, Mn, V or Fe) perovskite compounds. The total and partial densities of states of each solar perovskite RbVF3 (X = Co, Mn, Fe or V) material have been illustrated and discussed. In addition, the contribution of the different elements: Rb, Co, Mn, Fe, V and F, has been investigated revealing the most contributing ones in the valance and conduction bands. The magnetic behavior of the studied solar perovskites RbVF3 (X = Co, Mn, Fe or V) materials, has been outlined. It is found that the perovskites RbCoF3 and RbFeF3 are half‐metallic, while the materials RbMnF3 and RbVF3 exhibit a semi‐conductor behavior. [ABSTRACT FROM AUTHOR]

A series of bridged triazolo[4,5‐d]pyridazine based energetic materials were optimized at B3LYP/6‐311G(d, p) level of density functional theory (DFT), and their detonation properties and sensitivities were calculated. The results show that the NN bridge/N3 group were beneficial to improve values of heats of formation while NN bridge/C(NO2)3 group can improve detonation properties remarkably. In view of the sensitivities, compound F2 possesses the minimum values of impact sensitivity which reveals that NHNH bridge/C(NO2)3 group will decrease the stability of the designed compounds. Take both of detonation properties and sensitivities into consideration, compounds C8, E7, E8, F8 were screened as candidates of potential energetic materials since these compounds possess similar detonation properties and sensitivities values to those of RDX. All the calculated results were except to shine lights on the design and synthesis of novel high energy density materials. [ABSTRACT FROM AUTHOR]

As one of the representative perovskite‐type oxynitride photocatalysts, SrTaO2N has the ability to split water in the visible‐light region. It was found that the surface modification and interfacial design of SrTaO2N‐based materials are closely related to the photocatalytic activity, but the microscopic mechanisms of these experimental phenomena are not well understood. In this work, we have utilized density functional theory (DFT) calculations to investigate the effect of anion ordering and exposed terminations on the electronic structures, optical absorption, water adsorption and the mechanisms of water oxidation and reduction reactions of SrTaO2N. Our results indicate that cis configurations are more stable than trans configurations. The anion ordering has an important effect on the band gap and optical absorption coefficient. The terminations with exposed Ta atoms are more stable and have bigger work functions than those with exposed Sr atoms possibly due to the bonding ionicity and surface dipoles. The dissociative adsorption of water is energetically more favorable than the molecular adsorption on most surfaces. The highly active sites of hydrogen evolution reaction (HER) are the exposed nonmetal atoms. Terminations with exposed Sr and N atoms have lower overpotentials (0.70–0.77 V) of oxygen evolution reaction (OER) than others. They are comparable to the calculated results of common photocatalysts, such as Co3O4 and TiO2. This study sheds light on the relationship between the termination structure with different anion orders and the photocatalysis‐related properties of SrTaO2N at a molecular level, which provides guidance for constructing highly active photocatalytic materials. [ABSTRACT FROM AUTHOR]

First‐principles calculations based on density functional theory were used to study the adsorption behaviors of Na on metallic mono‐layered C4N as electrode materials for Na‐ion batteries. The adsorption energy of Na atom was calculated to be 2.05 eV, which is much higher than Na bulk cohesive energy and sufficiently ensure stability and safety. It is worth noting that the Dirac‐type band structure of mono‐layered C4N has a ultrahigh capacity of 1945.89 mAh/g for Na‐ion batteries anode in theory. Remarkably, 2D C4N has a low diffusion barrier 0.071 and 0.075 eV for path I and path II, respectively. The average open circuit voltage is 1.383 eV when nine Na ions adsorbed on one side of mono‐layered C4N. All the excellent properties show that the mono‐layered C4N will be a potential development of anode materials for Na‐ion batteries. [ABSTRACT FROM AUTHOR]

Using the pyrolyzing polymer‐salt compositions method yttrium orthochromite (space group Pnma) was synthesized. A value of oxygen nonstoichiometry δ=.056 and a band gap of 1.64 eV were obtained. With the experimentally determined structural parameters as a basis, we performed ab initio simulations to investigate the defect structure of YCrO3±δ. We studied the presence of interstitial oxygen in the YCrO3 at oxygen nonstoichiometry close to the experimental value and vacancies at the same concentration. Formation energies were estimated for interstitial oxygen atoms and compared with those of oxygen vacancies in the cases neutral and charged supercells. The computational results demonstrate that interstitial oxygen is energetically more favorable than the formation of oxygen vacancies. We considered various configurations of the interstitial oxygen atom within the YCrO3 crystal lattice and identified two fundamentally distinct types. An analysis of projected densities of states and charge distributions was performed for these configurations. The results indicate that direct intercalation of oxygen atoms is energetically more favorable than the formation of a peroxide species when the Fermi level is close to the conduction band minimum. [ABSTRACT FROM AUTHOR]

The rare earth element doped germanium cluster represents a fundamental nanomaterial and exhibits potential in next‐generation industrial electronic nanodevices and applied semiconductors. Herein, the cerium‐doped germanium anionic nanocluster CeGen− (n = 5–17) has been comprehensively investigated by the double hybrid density functional theory of mPW2PLYP associated with the unbiased global searching technique of artificial bee colony algorithm. The cluster's growth pattern undergoes three stages: n = 5–9 with the replaced structure, n = 10–15 with the linked structure, and n ≥ 16 forming a Ce‐encapsulated in Ge inner cage motif. The clusters' PES, IR, and Raman spectra were simulated, and their HOMO‐LUMO gap, magnetism, charge transfer, and relative stability were predicted. These theoretical values can serve as a reference for future experiments to some extent. Moreover, the special D2d symmetry cage geometry of CeGe16− leads to a higher stability and preferred energy gap, making it an ideal candidate for further studies on its aromaticity, UV–vis spectra, and chemical bonding characteristics. In summary, CeGe16− has excellent optical activity that can be potentially employed as a building block in the development of optoelectronic functional materials. [ABSTRACT FROM AUTHOR]

The development of efficient CO2 electrocatalytic reduction catalysts has become increasingly important. However, addressing issues related to activity and selectivity remains challenging due to the lack of robust design criteria. Organometallic sheets, characterized by their high surface area and well‐dispersed metal sites, offer a unique platform for catalysis. In this study, we employed large‐scale density functional theory calculations to investigate the transition metal dimers doped two‐dimensional extended phthalocyanines (TM2‐Pcs) as the biatom catalysts for the electrocatalysis of the CO2 reduction reaction (CO2RR). After systematical studies, the four catalysts of Mo2‐Pc, W2‐Pc, Ti2‐Pc, and Re2‐Pc were determined from 26 different TM2‐Pcs. Among them, Mo2‐Pc, Ti2‐Pc, and W2‐Pc have not only high faradaic efficiency (FE) but also small limiting potentials of reducing CO2 to CH4. Besides, the limiting potentials for the reduction of CO2 to CH2CH2 on Mo2‐Pc and Re2‐Pc fall within the range of −1.4 to −.8 V versus reversible hydrogen electrode. They demonstrate higher FE than the experimental results obtained on Cu(111). This work not only expands the possibilities for discovering more effective CO2 reduction catalysts but also provides a feasible strategy for the rational design of electrocatalysts CO2RR. [ABSTRACT FROM AUTHOR]

In this work, we report anomalous descriptions of bending modes of the carbon–carbon double bonded molecules with double hybrid density functional theories. The harmonic frequencies of the out‐of‐plane modes are found to be extremely low, and the anharmonicities are found to be very large. The unphysical large anharmonities of these modes increase significantly with a basis set having diffuse function. Increasing basis set size does not necessarily reduce or eliminate the problem. We observe that the problem with the double hybrid functional is in‐built due to the presence of the part of the second‐order perturbation terms in the functional. [ABSTRACT FROM AUTHOR]

Arsenic (As) frequently exists in pyrite (FeS2) in the form of impurities. The oxidation behavior of As in FeS2 is important in environmental science, mineral processing, and other related fields. The adsorption behaviors of H2O and O2 molecules on the As‐bearing pyrite (100) surface (AsFeS2(100)) are studied using the density functional theory (DFT). The results show that As prefers the S site on the pyrite (100) surface (FeS2(100)). In the absence of O2, an isolated H2O molecule does not dissociate when adsorbed at an iron (Fe) site and is repelled at an As site. Furthermore, the surface area around the As atoms exhibits a hydrophobic behavior. Adsorption energy analysis reveals that the presence of As atoms is unfavorable for the adsorption of H2O molecules on the pure FeS2 surface, and that the adsorption of H2O molecules on the AsFeS2(100) is physical adsorption. In the absence of H2O, it is suggested that the O2 molecule easily dissociates on both the pure FeS2(100) and AsFeS2(100). The adsorption of O2 on the As‐bearing surface is weaker than that on the pure FeS2(100). For the co‐adsorption of H2O and O2, the adsorption energy on the As‐bearing surface is more negative than that on the pure surface. This indicates that the presence of As promotes surface oxidation. Additionally, two OH and O (AsO or SO) or O (FeO) species are formed on the surface of pyrite when the H2O molecule is dissociated. [ABSTRACT FROM AUTHOR]

In this study, structural, electronic, optical and thermoelectric aspects of Zinc Sulfide (ZnS) and Zinc Telluride (ZnTe) have been explored in detail. These calculations have been done by utilizing FP‐LAPW method via Density Functional Theory (DFT). In order to attain accurate band gaps, opto‐electronic properties are evaluated with modified Becke Johnson potential (mBJ). From band structure plots, both ZnS and ZnTe reveals direct (Γv–ΓC) band gap semiconductors in nature with bandgap value equal to 3.5 and 2.3 eV while in Density Of States (DOS) major influence is observed due to p states of S/Te and d state of Zn. Prominent variation of optical responses such as high values of imaginary dielectric constants 휀1 (ω) and n (ω) refractive index suggests that ZnS and ZnTe are applicant materials for future photonics and microelectronic devices. The thermoelectric aspects were explored by Boltz Trap code to determine electrical and thermal conductivities, Seebeck coefficients, power factors and figure of merit. The figure of merits is closer to 1 while compared with p‐type ZnS and ZnTe, n‐type ZnS and ZnTe has good thermoelectric properties, which are attributed to low thermal conductivity of the hole and larger effective mass. The goal of this research is to investigate not only the detailed physical aspects but also to provide an overview of its future applications in optoelectronics, displays, sensors and microelectronic industry. [ABSTRACT FROM AUTHOR]

Density functional theory calculations are performed to analyze the structure and stability of Cu and Cu‐K clusters with 3 to 9 atoms. The results indicate that the stability of the clusters decreases after doping with a K atom. With the increase of cluster size, the stability of the clusters shows odd‐even alternation. Cu8 and Cu7K clusters exhibit the highest stability. Next, different adsorption sites are considered to investigate the geometry of CunNO and Cun−1KNO clusters. By calculating the adsorption energy and the HOMO‐LUMO energy gap, it is determined that both types of reactions are exothermic processes, indicating stable adsorption of NO. Notably, the CunK clusters are more active (stronger adsorption) for NO than the Cun clusters. The most chemically active clusters among CunNO and Cun−1KNO clusters are Cu8NO and Cu7KNO clusters. Finally, electron transfer and Mayer bond order analysis of Cu8NO and Cu7KNO clusters reveal that the NO bond order decreases due to electron transfer when Cu/Cu‐K clusters adsorb NO. In this process, the N atom is the electron donor and the Cu atom is the electron acceptor. Fundamental insights obtained in this study can be useful in the design of Cu/Cu‐K catalysts. [ABSTRACT FROM AUTHOR]

Understanding the electronic properties of silicon semiconductors is important for the preparation of high‐performance semiconductor materials. We calculated the band entropies, electronic structures, and bonding properties of a silicon semiconductor using density functional theory and the binding‐energy and bond‐charge model. The relationship between Si energy and temperature was studied using the tight binding (TB) approximation and bond‐order‐length‐strength (BOLS) theory (BOLS‐TB), with the Si (111) surface as an example. The specific binding energies and bonding properties of Si atoms in different surface atomic layers are discussed by analyzing the X‐ray photoelectron spectra of the Si (111) surface at 953 and 1493 K. This study improves our understanding of how surface properties reflect local bonding states and deepens our understanding of how atomic‐relaxation‐derived Hamiltonian perturbations and temperature influence the binding energy of the surface region. It also contributes to the development of Si‐based semiconductor materials by providing new ideas and methods. [ABSTRACT FROM AUTHOR]

A series of homo‐ (P0) and copolymers (P1‐P5) based on the electron‐donor building‐block 2,2′‐(2,3‐bis(2‐ethylhexyloxy)naphthalene‐1,4‐diyl)bis(ethyne‐2,1‐diyl)dithiophene (1,4‐NET) including ethynyl linkers aiming to promote coplanarity were designed, and their properties predicted using theoretical methodologies to evaluate their potential in organic solar cell applications. The geometries, FMO levels, energy bandgaps, and absorption spectra of trimer models were determined using time‐dependent density functional theory, while their photovoltaic and charge‐transport properties were estimated by the Scharber's model and semiclassical Marcus theory, respectively. Compared to high‐performance conjugated polymers (CPs), such as PTB7‐Th or PM6, and similar systems based on the 1D‐BDT unit, the HOMO and LUMO levels of P0‐P5 tend to be higher. In addition, the new CPs have complementary absorptions with narrow‐bandgap acceptors, such as ITIC and Y6, and adequate matches between their HOMO and LUMO levels. Although the simulated photovoltaic and charge‐transport properties could be overestimated, the best candidate to be synthesized and tested in organic solar cells is P5 due to its suitable and well‐balanced properties, demonstrating the positive effect of incorporating ethynyl bridges to improve the optoelectronic properties of CPs. [ABSTRACT FROM AUTHOR]

This study used periodic density functional theory and grand canonical Monte Carlo simulations to investigate the effects of the co‐doping of B and N atoms and substituting Zn2+ with Mg2+ or Ca2+ in the organic linker groups of MOF‐650. The functionalization increased the polarity of the organic groups, stabilizing the interaction between the MOF and hydrogen molecules. The highest average binding energy of the adsorbed hydrogen in MOF‐650 NB‐C7‐azulene‐Mg was calculated to be −4.75 to 5.40 kcal/mol for the α adsorption sites. Using the substitution of NB azulene and metal cations being Mg2+ or Ca2+, The hydrogen storage capacity of functionalized MOF‐650 was increased to 22 mg/g at 90 bar/298 K, implying the modification strategy of MOF‐650 would strengthen the interaction between MOF frameworks and hydrogen molecules. [ABSTRACT FROM AUTHOR]

Molecular iodine is found in many organic synthetic methodologies, both as reagent and as catalyst. Naturally, many groups have carried out computational studies involving this element. However, the choice of computational method proves to be more challenging than for other non‐metals. We quantify herein the errors that some common theory levels can introduce in terms of both structural and energetic deviations. We also evaluate multiple post hoc corrections, namely, vibrational entropy, dispersion, and counter‐poise corrections. Our results indicate the triple‐ζ basis sets are essential to obtain quality results and that post hoc corrections are overall detrimental. [ABSTRACT FROM AUTHOR]

This study employs density functional theory (DFT) and time‐dependent density functional theory (TD‐DFT) to investigate a series of cyclometallated Ir(III) complexes for their application as OLED light‐emitting materials, including (dtp)2Ir(dpm), (mmpyp)2Ir(dpm), (dtp)2Ir(tpip), (mmpyp)2Ir(tpip), (dtp)2Ir(pic), and (mmpyp)2Ir(pic). Their geometries, frontier molecular orbital properties, ionization potential, electron affinity, absorption and emission spectra, and spin‐orbit coupling properties have been analyzed respectively. Through comparison, we have identified complexes with reduced efficiency roll‐off and enhanced kISC. [ABSTRACT FROM AUTHOR]

The quantum treatment of electrons at the Kohn‐Sham Density Functional Theory (DFT) level of approximation is used in order to optimize the structure of four organic and organo‐metallic crystalline systems, starting from experimentally determined structures, allowing subsequent quantum‐level theoretical analysis, the accent here being put on crystals having nonlinear optical (NLO) properties. By employing DFT, one must select an exchange‐correlation functional (XCF), that is, a mathematical description of the electron interactions. Among most of the XCFs, a well‐known general discrepancy is the lack of London‐type interactions description. One of the most popular correction schemes consists of adding a posteriori the contribution of these interactions by using empirical expressions. Here, the approach relies on the simple D* scheme, a variation of the D2 correction originally elaborated by Grimme for molecular clusters, where the D2 correction is scaled to account for the interactions in the crystal solid state. The performance of this simple D* scheme is demonstrated and the most suitable scaling factors for four prototypical organic and organo‐metallic NLO crystals are determined for four representative XCFs: zero (no correction) for PBESol, PBESol0, and ωB97X, and 0.7 for B3LYP. [ABSTRACT FROM AUTHOR]

The structure and electronic properties of the biphotochromic dyad with two styrylbenzo[f]quinoline photochromes, as well as the corresponding cyclobutane with two benzo[f]quinoline (BQ) substituents, are studied by DFT at the M06‐2X/6‐31G* level, the cyclobutane being a product of the [2 + 2] photocycloaddition (PCA) reaction of the dyad. According to calculations, the dyad forms π‐stacked folded conformers, which, when excited, can form excimers that are precursors of cyclobutane. TD DFT calculations and natural transition orbital (NTO) analysis indicated that the lowest singlet excited S1 state in the dyad is localized on the SBQ photochrome, including the ethylene group that undergoes PCA. Thus, the conditions for concerted electrocyclic reactions are satisfied, and the direct PCA follows the Woodward–Hoffmann rules. In contrast, in cyclobutane, the S1 state is localized on the BQ substituent rather than on the cyclobutane core. Therefore, the reverse ring‐opening (retro‐PCA) reaction cannot follow the Woodward‐Hoffmann rules and inevitably involves a step of excitation energy transfer from BQ to cyclobutane, which means the predissociation mechanism. [ABSTRACT FROM AUTHOR]

The interaction behavior of HCl and (ZnS)n (n = 1–12) clusters and HCl effect on Hg0 adsorbed by (ZnS)n have been studied theoretically. The combined genetic algorithm and density functional theory (GA‐DFT) method has been used to obtain the structures of (ZnS)nHCl and (ZnS)nHgHCl (n = 1–12) clusters. The structural properties of (ZnS)nHCl and (ZnS)nHgHCl have been analyzed. The adsorption energies and interaction energies have been calculated. Bond length and bond order analysis has revealed that SH and ZnCl bonds form after HCl adsorbed on (ZnS)n clusters, while Hg0 can only weakly bind with (ZnS)nHCl clusters. According to thermodynamic adsorption analysis, the formation of (ZnS)nHCl clusters from (ZnS)n and HCl are spontaneous because of their negative Gibbs free energy changes. The formation of (ZnS)nHgHCl from (ZnS)nHCl and Hg are nonspontaneous for n = 1–4 and 9, and the Gibbs free energy changes have small negative values for other sizes. Electron localization function and noncovalent interaction (NCI) analysis of (ZnS)10HgHCl manifest that Hg and its nearest Zn form zinc amalgam. Projected density of state study has been performed to obtain the interaction nature of HCl and (ZnS)n clusters and Hg0 adsorption on (ZnS)nHCl clusters. Based on our study, HCl is chemical adsorbed by (ZnS)n clusters except (ZnS)4 cluster. After (ZnS)n adsorbs HCl, Hg0 can physically adsorb on (ZnS)nHCl clusters. The strength of Hg0 on (ZnS)nHCl is comparable to that of Hg0 on (ZnS)n, indicating that HCl can hardly affect the adsorption of Hg0 on ZnS clusters. [ABSTRACT FROM AUTHOR]

In order to identify high‐performance non‐fused ring electron acceptors for bulk heterojunction (BHJ) solar cells, six structurally diverse molecules are designed and categorized into two series. The first series is anchored by R1 as the reference molecule, featured fixed BDT, IC‐2F end groups and modified π bridges. The second series is anchored by R2 as the reference molecule, incorporated a terminal IC‐2F and a central core modified with EDOT bridge. The electronic structure and photoelectric properties of all acceptor molecules were investigated using density functional theory (DFT) and time‐dependent density functional theory (TD‐DFT). Charge transfer matrix (CTM), Density of states (DOS) and Reorganization energy (RE) etc. were analyzed to provide fundamental knowledge on charge transport and electronic excitation. Among the studied molecules, W2 exhibited a smaller energy gap (1.74 eV) compared to the other molecules, effectively transferring its electron from HOMO to LUMO. At the same time, the W2 molecule has excellent Voc and FF. Furthermore, W2 displayed the largest λmax redshift compared to R1. Although W3 had a smaller value of λh, the comprehensive photovoltaic parameters of W2 were more excellent. The research results not only demonstrated the feasibility of introducing different alkoxy groups to alter the structure of the π bridge and central core is a feasible method for constructing high‐performance NFREAs, but also highlighted that BDT cores combined with EDOT bridges are among the most promising small molecule acceptors (SMAs) that could be considered as reasonable candidates for synthesis and incorporation into organic solar cells. The results of this study are expected to provide seminal ideas for the design of high‐performance non‐fullerene acceptors. [ABSTRACT FROM AUTHOR]

The discovery of new and functional macrocyclic host compounds is an important part of supramolecular chemistry. Since the experimental synthesis, prism[n]arenes (Pr[n]As), a class of naphthol‐based macrocyclic arenes, have attracted much attention. In this work, from the perspective of theoretical calculation and research, Pr[n]As (n = 4 ~ 7) were studied by density functional theory (DFT) calculations and molecular dynamics (MD) simulations. The prismatic configuration isomers, electronic structures, absorption spectra, and host‐guest chemistry were discussed thoroughly. DFT calculation results showed that 1,5‐, 3,7‐, and "hybrid" 15,37‐Pr[n]As were the most representative configurations with the rigid prismatic molecular skeleton. Based on time‐dependent density functional theory (TD‐DFT), the absorption spectra of Pr[n]As were all in the range of ultraviolet light which were mainly attributed to π‐π* transitions. The molecular cavities of Pr[n]As were electron‐rich and capable of accommodating a variety of cations or electron‐conjugated molecules. MD simulation results showed that a Pr[n]A molecule was able to capture the guest molecule into its molecular cavity and maintain in the state of equilibrium in solvents. [ABSTRACT FROM AUTHOR]

We study the effects of the long‐range dispersive interaction on the electron transport in short single strands of guanine bases (G)s employing the density functional theory combined with non‐equilibrium Green's function method. Effects of contacting position are considered by connecting atomic gold chain electrodes on different positions to adapt to possible realistic measurements. The dispersive interaction can modify the stacking structure and enhance the helicity of the molecules. The corresponding change in the electronic structure may result in much‐increased conductance and the rectification effect. The dispersive interaction may also be the key to the realization of first‐principles simulation of some systems. [ABSTRACT FROM AUTHOR]

MXenes have wide applications because of the structural flexibility and compositional diversity. Quantum capacitance, electronic and photocatalytic properties of Sc2CO2 monolayer under uniaxial strains are investigated by first‐principles calculation. Sc2CO2 monolayer can withstand stress up to 13.96 N/M and about 14% tensile uniaxial strain limit. Sc2CO2 undergoes a transition from semiconductor to metal at −15% uniaxial strain. Sc2CO2 under uniaxial strains are only used for the water reduction at pH = 0. Sc2CO2 under uniaxial strains of −10%, −7%, −3%, 0%, and 4% within the appropriate pH scope are potential photocatalysts for water redox reaction. Sc2CO2 with −15% uniaxial strain is promising anode material, and Sc2CO2 with tensile uniaxial strain is more potential cathode material. Wide voltage improves the top quantum capacitance at negative bias under uniaxial strain and keeps the type of electrode materials. Quantum capacitance of Sc2C with mixed termination (Sc2CO0.59F1.19(OH)0.22) under uniaxial strain is explored. The introduction of uniaxial strain and mixed termination has little effect on the electrode type of Sc2CO2 MXene. [ABSTRACT FROM AUTHOR]

To investigate the isomerization transition of cluster ConMoS (n = 1–5), we employ density functional theory and transition state theory methods in this study. The cluster is optimized at the B3LYP/def2tzvp quantum chemical level. The results reveal eight isomerization reactions for the clusters ConMoS (n = 3, 5). Analyzing the activation energies shows a greater propensity for the isomerization transformation in the forward reaction compared to the reverse reaction. At room temperature, six isomerization transformation processes exhibit rapid conversion to the product configurations. Investigation of the equilibrium constants and application of the Arrhenius formula demonstrate that the cluster isomerization reactions are primarily driven by the forward reactions, with four reactions displaying efficient reactant to product conversion rates. Furthermore, there exists a consistent relationship between the structural complexity of the cluster and the change in entropy value. This study provides theoretical insights into reaction rates and optimization of reaction pathways, facilitating mutual validation and development between experimental and theoretical approaches. [ABSTRACT FROM AUTHOR]

The phase‐space relative Rényi entropy is introduced using the information theoretical and thermodynamic view of density functional theory. In the special case of constant inverse temperature the phase‐space relative Rényi entropy is a sum of the position‐space relative Rényi entropy and a term arising from the momentum space. This quantity can be considered as a measure of similarity. It includes more information than the position‐space measures, since it also incorporates momentum‐space knowledge. [ABSTRACT FROM AUTHOR]

In this paper, the systematic theoretical study of phenol and 36 compounds representing various ortho, meta and para‐substituted (R‐PhOH) phenols is presented. The hydroxyl group acidity is a characteristic feature of phenol which can be modified using substitution of phenyl ring. The proton‐coupled electron transfer was investigated for parent neutral phenols, R‐PhOH, their cation radicals, R‐PhOH+•, and oxonium cations, R‐PhOH2+. Density functional theory calculations were combined with solvent continuum model for water and dimethyl sulfoxide environment. For aqueous solution, the Pourbaix diagrams (electrochemical potential vs. pH) were constructed from the theoretically predicted acidity constants and electrochemical standard potentials. From the thermodynamic point of view, the obtained theoretical results allow the estimation of the thermodynamically preferred process and alternative reaction pathways of phenolic derivatives in very acidic media. [ABSTRACT FROM AUTHOR]

Azoheteroarenes represent an attractive group of photochromes exhibiting a large structural variability and tunability of photoswitching characteristics. The thermal back‐isomerization can proceed via inversion or rotation mechanisms, depending on the functionalization and environment. However, the distinction between the two remains a challenge for both experiment and theory. Here, four experimentally fully characterized phenylazoindoles are studied to establish the mechanism of back‐reaction in solvent using density functional theory (DFT), spin‐flip time‐dependent (TD‐)DFT, mixed‐reference TD‐DFT, and restricted ensemble Kohn–Sham approaches as well as CASPT2 and CCSD(T). While the inversion is consistently described by all methods, the rotation mechanism requires multireference approaches including dynamic correlation. The balanced description of both pathways becomes even more important in solvent which apparently affects the mechanism. For the present set, the range‐separated functionals combined with continuum models appear to be the most consistent with experiment in terms of the substitutional and solvent effects on thermal halftimes. [ABSTRACT FROM AUTHOR]

Cation‐π interactions are theoretically investigated for alkali metal cation (M+)‐circumcoronene (CC) complexes (M = Li, Na, K), in gas phase and in aqueous solution with consideration of micro‐ and global solvation models using the DFT/PBEh‐3c‐RI/TZVP method. The solvent effect on the M+–CC energy interaction regarding the cation size and the stability of inner‐ and outer‐sphere [M(H2O)n]+–CC complexes are calculated by means of geometry optimizations and potential energy (PE) curves. The PE curves, calculated as a function of perpendicular distance of M+ to the CC plane, predicted one energy minimum for each of the isolated M+–CC complexes. However, for microhydrated complexes, two minima assigned to two different surface complexations were obtained. Microhydrated Li+ and Na+ favored outer‐sphere complexation while inner‐sphere complexation was found more stable for microhydrated K+. These results illustrate nicely the key role, which the cation radius plays for the polarization of the water molecules and the aromatic system. [ABSTRACT FROM AUTHOR]

The reactions of limonene with various free radicals (•OCH3, •OBr, •SH, •OOH, and •OOCH3) were investigated along the 273.15–312.15 K temperature range. To that purpose the density functional theory was used, at the M06‐2X/6–311+g(d,p) level. Two reaction mechanisms, hydrogen atom transfer (HAT) and radical adduct formation (RAF) were considered. It was found that the relative reactivity of the studied radicals toward limonene is: •SH > •OBr > •OCH3 > •OOH > •OOCH3. HAT was identified as the dominant mechanism for •OOH and •OOCH3, while RAF contributes the most to the reactions involving •OCH3, •OBr, and •SH. The obtained Arrhenius expressions are: k(•OCH3) = 1.58 × 10−13 e−1.59/RT, k(•OBr) = 3.55 × 10−12 e+1.82/RT, k(•SH) = 3.30 × 10−11 e+0.79/RT, k(•OOH) = 1.33 × 10−15 e−5.99/RT, and k(•OOCH3) = 5.88 × 10−17 e−6.26/RT. According to them, the reactions of •OBr and •SH become slower as temperature rises from 273.15 to 312.15 K, while for the other radicals the reactions rate increases with temperature. The subsequent tropospheric fate of the most abundant •OBr adduct was also investigated in the same temperature range, considering O2 addition to this radical (step 2) and the reaction of the peroxyl radical yielded in this step 2 with NO. The latter is predicted to take place in two steps: the NO addition (3a) and the NO2 elimination (3b). The corresponding Arrhenius expression are k2 = 3.56 × 10−15 e+1.43/RT and k3b = 1.35 × 1014 e−31.65/RT. Step 3a was found to be barrierless. To our best knowledge, all the data provided here is reported for the first time. Thus, it would hopefully contribute to enhance the knowledge necessary for the full understanding (and accurate modeling) of the troposphere. [ABSTRACT FROM AUTHOR]

The bond dissociation energies (BDE) of most main‐group elements have been accurately measured. However, the BDE values for heavy elements, particularly those from the fifth period (InI), are still missing or poorly validated. This study aims to identify the most accurate computational methods for calculating BDE values of compounds containing fifth‐row elements, including In, Sn, Sb, Te, and I, with a focus on readily accessible methods in software packages. The investigation involved a benchmark study using density functional theory (DFT), in addition to the 2nd order Møller–Plesset perturbation theory (MP2) and the coupled cluster with single, double, and perturbative triple excitations CCSD(T). The DFT functionals used in the study include APFD, B3LYP, B3LYP‐D3, B3P86, B97‐D3, BHandH, HSEH1PBE, M06‐2X, MN12‐SX, MN15‐L, and TPSSH. The functionals were carefully selected to cover some popular functionals as well as to cover all levels of the Jacob's ladder of DFT accuracy. The computed BDE values were compared with experimental values, and the results were filtered to remove any possible outliers. The statistical errors (MAPE, RMSE, and Pearson's) were then calculated and used to assess the performance of the methods. [ABSTRACT FROM AUTHOR]