Molecular constants have been computed for the ground states 2∏ of 17OH and 1Σ of 107AgH+. The valence-bond method and advanced computational technique were used to perform all-electron ab initio calculation of molecular electronic structures. The basic idea behind the model is to introduce the molecular wave functions in terms of Hartree-Fock many-electron atomic determinants. Full configurati...

The Hoyle state plays a crucial role in the helium burning of stars heavier than our Sun and in the production of carbon and other elements necessary for life. This excited state of the carbon-12 nucleus was postulated by Hoyle as a necessary ingredient for the fusion of three alpha particles to produce carbon at stellar temperatures. Although the Hoyle state was seen experimentally more than a...

This article addresses a fundamental problem faced by the ab initio community: the lack of an effective formalism for the rapid exploration and exchange of new methods. To rectify this, we introduce a novel, basis-set independent, matrix-based formulation of generalized density functional theories which reduces the development, implementation, and dissemination of new ab initio techniques to th...

For I-(H 2 O) 4 cluster, it has long believed that the C 4 symmetry structure is most stable isomer at low temperature. However, calculated vibrational spectra values using ab initio disagree with experimental values. Therefore, we calculated the structure of I-(H 2 O) 4 using extensive ab initio calculation. Hence, we found most stable isomer for I-(H 2 O) 4 at low temperature. The isomer has ...

In this paper, we explore the numerical feasibility of carrying out quantum dynamics calculations from ab initio points for gas phase chemical reactions. In this approach, the ab initio data are Ðrst generated from quantum chemistry programs on a coarse numerical grid and a quantum dynamics calculation is then carried out using data from these grids. A crucial step in the success of this method...

Recently, we introduced a new density-functional theory ~DFT! approach for the calculation of NMR shielding constants. First, a hybrid DFT calculation ~using 5% exact exchange! is performed on the molecule to determine Kohn–Sham orbitals and their energies; second, the constants are determined as in nonhybrid DFT theory, that is, the paramagnetic contribution to the constants is calculated from...