Ab initio study of the molecular vibrations and electronic structure of the X, B, D and F 2Σ + states of AlO

Abstract

Molecular vibrations and electronic structure of the X 2Σ +, B 2Σ +, D 2Σ +, and F 2Σ + states of AlO are studied by carrying out ab initio configuration interaction calculations and molecular vibration calculations using accurate potential energy functions. An avoided crossing between the D 2Σ + and F 2Σ + potential energy curves occurs in the neighborhood of 4.0 a 0 and results in irregular vibrational levels of the D and F 2Σ + states. The vibrational constants for the F 2Σ + state are predicted from the vibrational levels not involved in the irregularity. Configuration mixing is important in describing the B, D, and F 2Σ + states. The F 2Σ + state at and around its well minimum and the D and F 2Σ + states in the avoided crossing region are characterized in terms of their main configurations and dipole moment functions.