Influence of basis-set size on the XΣ1/2+2 , A

Abstract

potential energy curves for Rb + He are computed at the spin-orbit multi-reference configuration interaction level of theory using a hierarchy of Gaussian basis sets at the double-zeta (DZ), triple-zeta (TZ), and quadruple-zeta (QZ) level of valence quality. Counterpoise and Davidson-Silver corrections are employed to remove basis set superposition error and ameliorate size consistency error. An extrapolation is performed to obtain a final set of potential energy curves in the complete basis set limit (CBS). This yields four sets of systematically improved X 2 Σ + 1/2 , A 2 Π 1/2 , A 2 Π 3/2 and B 2 Σ + 1/2 potential energy curves that are used to compute the A 2 Π 3/2 bound vibrational energies, the position of the D2 blue satellite peak, and the D1 and D2 pressure broadening and shifting coefficients, at the DZ, TZ, QZ, and CBS level. Results are compared with previous calculations and experimental observation.

Ab Initio Study of the Interaction Potentials of CF-=SUB=-4-=/SUB=-, CH-=SUB=-4-=/SUB=-, SiF-=SUB=-4-=/SUB=- and SiH-=SUB=-4-=/SUB=- Molecules with the Rb Atom in the Ground and Electronically Excited States

“…In this case, for bases with a smaller contraction the value of (B, X) max is smaller than for the bases with a larger contraction. Note that the calculations of the RbHe molecule using basis sets of various sizes revealed similar tendencies [10].…”

“…As can be seen from Figs 1 and 2, the B state potential has a singularity in the form of an inflection or even a local minimum located approximately in the same region of the internuclear distance where the maximum of the difference potential (B, X) is located. This feature has been discussed many times before [6][7][8][9][10]. The deviation from a smooth increase in the repulsion energy with decreasing internuclear distance is based on the configurational interaction of the B state with higher-lying states of the same symmetry ( 2 + in the case of a diatomic RbAr molecule).…”

“…This article also discusses the results of calculations for the diatomic RbAr molecule. The electronic structure of RbAr and other RbRg molecules (Rgan atom of an inert gas) has been repeatedly studied earlier using quantum chemistry methods [6][7][8][9][10]. Compared to RbXY 4 , RbAr calculations are much less time consuming.…”

A fully quantum calculation of broadening and shifting coefficients of the D1 and D2 spectral lines of alkali-metal atoms colliding with noble-gas atoms

“…Testing different sorts of potentials with more localized and controllable characteristics might give more information and confirmation about what parts of the potential energy surfaces give rise to which characteristics in the broadening and shift rates and intermediate calculations such as the scattering phase shift differences. There is work ongoing to generate better potential energy surfaces [38] and to utilize them to simulate reactions involving the higher manifolds [39].…”

Квантово-химическое исследование потенциалов взаимодействия молекул CF-=SUB=-4-=/SUB=-, CH-=SUB=-4-=/SUB=-, SiF-=SUB=-4-=/SUB=- и SiH-=SUB=-4-=/SUB=- с атомом Rb в основном и электронно-возбужденных состояниях

“…При этом для базисов с меньшим сжатием величина (B, X) max меньше, чем для базисов с большим сжатием. Отметим, что расчеты молекулы RbHe с использованием базисов различного размера выявили аналогичные тенденции [10].…”