In the first paper of this series, a very accurate ab initio potential energy curve of the (3)Sigma(g)(-) ground state of O(2) has been determined in the approximation that all valence shell electron correlations were calculated at the complete basis set limit. In the present study, the corrections arising from core electron correlations and relativity effects, viz., spin-orbit coupling and sca...

In this paper we presented a method for determination the lower state energies, and hence the rotational quantum number, in the overtone spectra of methane (the Icosad polyad, between 7076 to 7291 cm). The method explores the temperature dependence of rovibrational transition intensities. In the first part of this report this approach is used with spectra measured at a) 81 K in liquid nitrogen ...

A theoretical study of the kinetic and mechanism of 3-aug-Cope rearrangement in gas phase was performed usingDET methods at B3LYP levels of theory with 6-3114iG(d,p) bass set at 298.I5K. Equilibrium moleculargeometries and harmonic vibrational frequencies of the reactant, transition state Did product were calculated. Then,rate constant and activation thermodynamics parameters were calculated an...

We present a model describing ionization and excitation of nitrogen molecules by strong short laser pulse. Different from previous publications, both processes are considered within the same formalism density matrix. account for dependence dipole moment on vibrational quantum number large excited levels. Populations levels depend significantly intensity, wavelength, polarization, pulse duration.

Precision measurements with ultracold molecules require development of robust and sensitive techniques to produce and interrogate the molecules. With this goal, we theoretically analyze factors that affect frequency measurements between rovibrational levels of the Sr2 molecule in the electronic ground state. This measurement can be used to constrain the possible time variation of the proton-ele...

A comprehensive, calculated line list of frequencies and transition probabilities for the singly deuterated isotopologue of H3 , H2D +, is presented. The line list, called ST1, contains over 22 million rotational-vibrational transitions occurring between more than 33 thousand energy levels; it covers frequencies up to 18 500 cm−1. All energy levels with rotational quantum number, J, up to 20 ar...

In recent years there has been considerable interest in the structures, energies and thermodynamics of(GaN)4 clusters and it is the subject of many experimental and theoretical studies because of theirfundamental importance in chemical and physical process. All calculation of this study is carried outby Gaussian 98. Geometry optimization for (GaN)4 nanocluster are be fulfilled at B3LYP, B1LYPan...