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Based on the first-principles, the hydrogen storage, mechanical, electronic, optical, thermodynamic and kinetic properties of XPtH 3 (X = Li, Na, K, Rb) perovskites are investigated for the first time in this work. The lattice constants of the optimized LiPtH 3 , NaPtH 3 , KPtH 3 , and RbPtH 3 are 3.54, 3.63, 3.80, and 3.90 Å, respectively. The Cauchy's pressure and the ratio of the bulk modulus to shear modulus (B/G) consistently prove that the XPtH 3 hydrides all exhibit ductility. The investigation of electronic properties reveals that XPtH 3 compounds exhibit metallic nature. According to Poisson's ratio and charge density distribution, the bonding type of XPtH 3 hydrides is mainly ionic. The Bader partial net charges are also calculated to analyze the charge transfer in XPtH 3 perovskites. The results of the optical properties of XPtH 3 compounds reveal that they are high dielectric constant and high refractive index materials. It is found that the XPtH 3 perovskites exhibit thermodynamic, mechanical, and dynamic stability. The gravimetric hydrogen storage capacities are 1.45, 1.35, 1.26, and 1.06 wt% for LiPtH 3 , NaPtH 3 , KPtH 3 , and RbPtH 3 , respectively. The hydrogen desorption temperatures of LiPtH 3 , NaPtH 3 , KPtH 3 and RbPtH 3 are 237.77, 225.39, 162.43, and 80.11 K, respectively. Our results suggest that LiPtH 3 hydride is the most suitable material for hydrogen storage applications among the four compounds. Systematic calculation of the physical and hydrogen storage properties of XPtH 3 (X = Li, Na, K, Rb) for the first time. Moreover, XPtH 3 (X = Li, Na, K, Rb) hydrides are thermodynamically, mechanically, and dynamically stable. Our results provide new candidates for hydrogen storage materials. [Display omitted] • XPtH 3 (X = Li, Na, K, Rb) perovskites have been investigated using first-principles. • XPtH 3 compounds exhibit thermodynamic, mechanical, and dynamical stability. • The gravimetric hydrogen storage capacity is found to be 1.45 wt% for LiPtH 3. [ABSTRACT FROM AUTHOR]

The perovskite-type hydride compounds are potential candidate materials in the field of hydrogen storage. This paper presents a systematical study of XTiH 3 (X = K, Rb, Cs) using density functional theory. The analysis of formation energy, elastic properties and phonon dispersion curves indicate that all the studied materials are thermodynamically, mechanically and dynamically stable. By analyzing the B/G ratio, it is determined that these compounds are brittle materials. The electronic properties reveal that the XTiH 3 compounds exhibit semi-metallic characteristics. The charge transfer characteristics of these compounds were analyzed using Bader partial charges. Moreover, the thermodynamic characteristics of these compounds were investigated and the dependence of their free energy, entropy and heat capacity on the temperature were analyzed. Finally, the gravimetric hydrogen storage capacities of KTiH 3 , RbTiH 3 and CsTiH 3 were calculated to be 3.36, 2.22 and 1.65 wt%, respectively. The hydrogen desorption temperatures of KTiH 3 , RbTiH 3 and CsTiH 3 were found to be 209 K, 161 K and 107 K, respectively. To our knowledge, this study represents the very first investigation of XTiH 3 compounds and offers valuable references to this hydrogen storage material. [Display omitted] • XTiH 3 (X = K, Rb, Cs) perovskite have been investigated using first-principles. • XTiH 3 perovskite exhibit thermodynamic, mechanical and dynamical stability. • The gravimetric hydrogen storage capacity is found to be 3.36 wt% for KTiH 3. [ABSTRACT FROM AUTHOR]

Topological Hall effect, being an unconventional anomalous Hall effect, is originated from the real‐space Berry curvature caused by the nontrivial topological spin textures in materials. Manipulations of nontrivial magnetic structure and related topological Hall effect are very important for the study of the chiral magnet. Herein, it is experimentally observed that the significant topological Hall conductivity σxy in antiferromagnetic K0.5RhO2 can reach 3.5% of ν = 1 quantum conductivity below 20 K. Furthermore, by adjusting the concentration of K‐cation different from 0.5 in KxRhO2 or substituting the K cations by Rb or Cs to form Rb0.5RhO2 or Cs0.5RhO2, it is observed that the topological Hall effect is much weakened or even disappeared. This evolution, verified by the theoretical calculations, is attributed to the unstable ground state of the non‐coplanar spin structure in KxRhO2 (x = 0.4 and 0.6) and Cs0.5RhO2. The significantly tunable topological Hall effect in AxRhO2 makes it prospective on logical/sensor devices of spintronics. [ABSTRACT FROM AUTHOR]

• Alkali metals and alkali earth metals are group one and group two elements on the periodic table and are known to exert highly reactive chemical properties. • This case-control study aimed to evaluate the association between alkali metals and alkali earth metals and schizophrenia. • We found that higher magnesium and strontium serum levels were associated with schizophrenia. • Most of alkali metals and alkali earth metals were not correlated to the severity of schizophrenia, except for Ba. Alkali metals (AMs) and alkali earth metals (AEMs) affect levels and signaling of neurotransmitters, which potentially play a role in the etiology of schizophrenia (SCZ). The current case-control study aims to explore how AMs [i.e. Potassium (K), sodium (Na), rubidium (Rb), cesium (Cs)] and AEMs [i.e. magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba)] in serum could associate with SCZ. One hundred and five inpatients with SCZ and 106 age- and sex-matched healthy controls (HCs) were recruited from Weifang, China. Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES) was used to evaluate serum concentrations of Na, K, Ca, Mg and Inductively Coupled Plasma Mass Spectrometry (ICP-MS) was for Rb, Cs, Sr, Ba. Subjects with SCZ had significantly higher Mg and Sr serum concentrations than HCs (20.86 vs. 19.73 μg/mL of Mg, p < 0.001; 53.14 vs. 42.26 ng/mL of Sr, p < 0.001). After adjusting for confounders, the odds ratio of Mg and Sr remain significantly higher in the SCZ group (Mg: OR = 2.538, 95 % CI: 1.254–5.136, p= 0.010; Sr: OR = 3.798, 95 % CI: 1.769–8.153, p = 0.001). No significant differences between SCZ subjects and HCs were observed for other AMs and AEMs. Higher serum concentrations of Mg and Sr were associated with SCZ. Studies are suggested to find the related mechanisms and provide clues for pathogenesis of SCZ, which would impact prevention and treatments of SCZ. [ABSTRACT FROM AUTHOR]

The perovskite-type hydrides are potential candidate materials for the hydrogen storage. On the basis of the first-principles calculations, the hydrogen storage, mechanical, electronic, optical, thermodynamic and kinetic properties of XMnH 3 (X = Na, K, Rb) perovskites are investigated in this paper. The lattice constants of the optimized NaMnH 3 , KMnH 3 , and RbMnH 3 are 3.59, 3.89, and 4.05 Å, respectively. The Poisson's ratio, Cauchy's pressure, and B/G consistently prove that all of the XMnH 3 hydrides are brittle. The exploration of electronic properties reveals that NaMnH 3 exhibits metallic behavior, while KMnH 3 and RbMnH 3 exhibit half-metallic behavior. According to the charge density distribution and Poisson's ratio, both ionic and covalent bonds exist in XMnH 3. The Bader partial net charges are also calculated to analyze the charge transfer in XMnH 3. The results of optical properties of XMnH 3 show that NaMnH 3 has the largest static dielectric constant and static refractive index. Based on the formation energy, Born stability criterion, and phonon dispersion curve, it is demonstrated that XMnH 3 compounds have thermodynamic, mechanical, and dynamic stability. The gravimetric hydrogen storage capacities are 3.74, 3.12, and 2.11 wt% for NaMnH 3 , KMnH 3 , and RbMnH 3 , respectively. Above investigations suggest that NaMnH 3 is the most suitable hydrogen storage material among the three compounds. • XMnH 3 (X = Na, K, Rb) perovskites have been investigated using first-principles. • XMnH 3 compounds exhibit thermodynamic, mechanical, and dynamical stability. • The gravimetric hydrogen storage capacity is found to be 3. 74 wt% for NaMnH 3. [ABSTRACT FROM AUTHOR]