A simple modification of the zeroth-order regular approximation (ZORA) in relativistic theory is suggested to suppress its erroneous gauge dependence to a high level of approximation. The method, coined gauge-independent ZORA (ZORA-GI), can be easily installed in any existing nonrelativistic quantum chemical package by programming simple one-electron matrix elements for the quasirelativistic Ha...

Detergents are customarily used to solubilize cell membranes and keep membrane proteins soluble in aqueous buffers, but they often lead to irreversible protein inactivation. Hemifluorinated amphiphiles with hybrid hydrophobic chains have been specifically designed to minimize the denaturating propensity of surfactants toward membrane proteins. We have studied the physical-chemical and biochemic...

The IR and Raman spectra of the title compound have been recorded and analyzed. The harmonic vibrational wavenumbers were calculated theoretically using Gaussian09 software package. Calculations were performed by HF and DFT levels using the standard 6-31G* basis sets. The data obtained from vibrational wavenumber calculations are used to assign vibrational bands found in the IR and Raman spectr...

The high-temperature oxidation of Hf-modified NiAl alloy at 950 °C results in the formation γ-Al2O3 and θ-Al2O3. Exclusive HfO2 particles is observed adherent γ-Al2O3/NiAl interface. By contrast, θ-Al2O3/NiAl interface multi-layered oxide growth consisting alternate thin thick layers θ-Al2O3 NiAl2O4 along with dispersed layers. This difference elucidated by first-principle calculations showing ...

ABSTRACT We present the first set of rate coefficients for rotational excitation 7 lowest levels hydrogen fluoride (HF) induced by collision with water molecules, dominant collider in cometary comas, 5–150 K temperature range. The calculations are performed a quantum statistical approach from an accurate rigid rotor ab initio interaction potential. Rate HF electron-impact also computed, within ...

The static and dynamic magnetic properties of a pentacoordinate [Co(phen)(DMSO)Cl2] compound (phen = 1,10'-phenanthroline, DMSO = dimethyl sulfoxide) were thoroughly studied by experimental (SQUID magnetometry and HF-EPR spectroscopy) and theoretical methods (DFT and CASSCF calculations). It has been found from temperature/field-dependent magnetization measurements that the studied compound pos...

A hybrid quantum mechanical/molecular mechanical (QM/MM) potential energy function with Hartree-Fock, density functional theory (DFT), and post-HF (RIMP2, MP2, CCSD) capability has been implemented in the CHARMM and Q-Chem software packages. In addition, we have modified CHARMM and Q-Chem to take advantage of the newly introduced replica path and the nudged elastic band methods, which are power...

We developed a program code of configuration interaction singles (CIS) based on a numerical grid method. We used Kohn-Sham (KS) as well as Hartree-Fock (HF) orbitals as a reference configuration and Lagrange-sinc functions as a basis set. Our calculations show that KS-CIS is more cost-effective and more accurate than HF-CIS. The former is due to the fact that the non-local HF exchange potential...

Most approximations to the exchange-correlation functional of Kohn-Sham density functional theory lead to delocalization errors that undermine the description of charge-transfer phenomena. We explore how various approximate functionals and charge-distribution schemes describe ground-state atomic-charge distributions in the lithium-benzene complex, a model system of relevance to carbon-based sup...