Diatomics-in-molecules models for H2O and H2O−. II. A self-consistent description of the 1A′, 1A″, 3A′, and 3A″ states of H2O

Abstract

This paper describes a small (6 to 9 basis functions) model for the potential energy surfaces relevant to the chemical reaction O(1D)+H2→OH(X 2Π)+H. The model is optimized with respect to the 1A′ and 1A″ states correlating with the reagents and products of this reaction; this is done in such a way as to simultaneously provide a qualitatively correct description of the 3A′ and 3A″ states of H2O. In this sense the model is self-consistent. In agreement with other semiempirical work, the results indicate that two 1A′ surfaces and one 1A″ surface are pertinent for a dynamical study of this reaction. The model adequately represents the most important features of H2O potential energy surfaces and is at the same time small enough to be used directly in a trajectory calculation of the reaction cross section.