Accurate ab initio potential energy curve of O2. II. Core-valence correlations, relativistic contributions, and vibration-rotation spectrum

摘要: In the first paper of this series, a very accurate ab initio potential energy curve Σ3g− ground state O2 has been determined in approximation that all valence shell electron correlations were calculated at complete basis set limit. present study, corrections arising from core and relativity effects, viz., spin-orbit coupling scalar relativity, are added to curve. From 24 points on curve, an analytical expression terms even-tempered Gaussian functions is and, it, vibrational rotational levels by means discrete variable representation. We find 42 levels. Experimental data (from Schumann–Runge band system) only yield lowest 36 due significant reduction transition intensities higher For 35 term values G(v), mean absolute deviation between theoretical experimental 12.8 cm−1. T...