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A semi-empirical IR/Vis line list, SOLIS, for the sulphur monoxide molecule 32S16O is presented. SOLIS includes accurate empirical rovibrational energy levels, uncertainties, lifetimes, quantum number assignments, and transition probabilities in the form of Einstein A coefficients covering the |$X\, {}^{3}\Sigma ^{-}$| |$, a\, {}^{1}\Delta , b\, {}^{1}\Sigma ^{+}, A\, {}^{3}\Pi , B\, {}^{3}\Sigma ^{-}, A^{\prime \prime }\, {}^{3}\Sigma ^{+}, A^{\prime }\, {}^{3}\Delta$|⁠ , and |$e\, {}^{1}\Pi$| systems and wavenumber range up to 43 303.5 cm−1 (≥230.93 nm) with J ≤ 69. SOLIS has been computed by solving the rovibronic Schrödinger equation for diatomics using the general purpose variational code Duo and starting from a published ab initio spectroscopic model of SO (including potential energy curves, coupling curves, (transition) dipole moment curves) which is refined to experimental data. To this end, a database of 50 106 experimental transitions, 48 972 being non-redundant, has been compiled through the analysis of 29 experimental sources, and a self-consistent network of 8558 rovibronic energy levels for the X, a, b, A, B , and C electronic states has been generated with the marvel algorithm covering rotational and vibrational quantum numbers J ≤ 69 and v ≤ 30 and energies up to 52 350.40 cm−1. No observed transitions connect to the |$B\, {}^{3}\Sigma ^{-}$| (v  = 0) state which is required to model perturbations correctly, so we leave fitting the |$B\, {}^3\Sigma ^-$| and |$C\, {}^3\Pi$| state UV model to a future project. The SO line list is available at ExoMol from www.exomol.com. [ABSTRACT FROM AUTHOR]

The membrane protein Niemann‐Pick type C1‐like 1 (NPC1L1) plays a central role in the absorption of cholesterol in the small intestine. Other sterols, notably vitamin E and vitamin K1 also utilize NPC1L1 as a membrane transporter even though other absorption paths exist. Many NPC1L1 mutations causing the disease due to poor transport of cholesterol are known. It is not clear at this moment if the same mutation can lead to reduced transport behavior with these vitamins. In this study, we have obtained the binding free energies of these two sterols using molecular dynamics simulation and compared these values with the cholesterol‐binding free energy. The N‐terminal domain (NTD) of the wild as well as the disease‐causing two mutations, T61M and L110F, are used for this purpose. The result indicates that the mutations show reduced binding affinity compared to the wild except for the vitamin K1 in the T61M mutant, which has increased binding free energy. Also, we found the similarity of the key amino acids responsible for the change of free energy by mutation between T61M and L110F. At the same time, non‐negligible differences exist also. [ABSTRACT FROM AUTHOR]

The CCSD(T)/6-311+G(3df,2p)//QCISD/6-311G(d,p) method was used to study the lowest triplet state potential energy surface of the C((super 3)P) +CH4 reaction. Two reaction mechanisms were found - H-atom abstraction leading to the CH + CH3 products and insertion of the carbon atom into methane's C-H bond leading to the triplet HC-CH3 intermediate followed by its isomerization to triplet ethylene and or decomposition through the elimination of a hydrogen atom.

The 1,2,4,7-cyclooctatetraenyl radical (C8H7) has been synthesized for the very first time via the bimolecular gas-phase reaction of ground-state carbon atoms with 1,3,5-cycloheptatriene (C7H8) on the triplet surface under single-collision conditions. The barrier-less route to the cyclic 1,2,4,7-cyclooctatetraenyl radical accesses exotic reaction intermediates on the triplet surface, which cannot be synthesized via classical organic chemistry methods: the triplet non-aromatic 2,4,6-cyclooctatriene (C8H8) and the triplet aromatic 1,3,5,7-cyclooctatetraene (C8H8). Our approach provides a clean gas-phase synthesis of this hitherto elusive cyclic radical species 1,2,4,7-cyclooctatetraenyl via a single-collision event and opens up a versatile, unconventional path to access this previously largely obscure class of cyclooctatetraenyl radicals, which have been impossible to access through classical synthetic methods. [ABSTRACT FROM AUTHOR]

Carbon-rich radicals are important for understanding chemistry of flames as well as astrochemistry. However, they are elusive for both experiments and computations, due to the peculiarity of radicals. Here, we calculated excited states of the 1-buten-3-yn-2-yl ( HCCCCH2 , i- C4H3 ) and n- C4H3 ( HCCCHCH) radicals with the state-of-the-art complete active space self-consistent field ( CASSCF) and multi-reference configuration interaction ( MRCI) methods using the 6-311 + G(3df,2p) and aTVZ basis sets. The vertical energies for the seven excited states of each of the two isomers were obtained with the MRCI method at the geometries optimized at the CASSCF/6- 311G(d,p) level. The result using the aTVZ basis set has been more reliable than predicted with the 6-311 + G(3df,2p) basis set with the relative stability of the ground states of the two isomers better predicted in comparison to existing data. We believe that our results will be useful for understanding the chemistry of carbon-rich radicals. [ABSTRACT FROM AUTHOR]

HOSO[sub 2] radical is the key intermediate for the oxidation SO[sub 2] to SO[sub 3] by OH radical in the atmosphere. The structural aspects and the energetics of the reaction HOSO[sub 2]+O[sub 2]→SO[sub 3]+HO[sub 2] have been studied using Mo\ller-Plesset (MP2) and density functional (DFT) techniques with 6-31G[sup **] and triple-ζ, quadruple-ζ, and quintuple-ζ quality basis sets including diffuse basis functions. The detailed theoretical analyses have further revealed that this reaction could proceed through the formation of intermediate complexes and an intramolecular proton transfer like transition state. The energetics of these intermediate reactions has been studied in detail. The use of MP2 methods to study such radical mechanisms had some characteristic symmetry-breaking problem with larger basis sets. This unphysical situation with larger basis set MP2 calculations in this hypervalent system has been explained through the interpretation of the relevant energy surface. © 2000 American Institute of Physics. [ABSTRACT FROM AUTHOR]