Ab initiostudy of NO2

Abstract

Three-dimensional polynomial fits to ab initio CI potential surfaces computed for the two lowest electronic states of the NO2 molecule are reported in both the adiabatic and diabatic representations. Structural and spectroscopic parameters resulting from the calculated surfaces are found to be in good agreement with known experimental data. In addition, various energy contour diagrams are presented to aid in the visualization of the conical intersection which characterizes these two potential surfaces and is widely thought to be largely responsible for the chaotic appearance of the NO2 spectrum.