The [formula omitted] reaction. A density functional theory study

Abstract

The potential energy surface for the O( 3 P)+ HBr( χ 1 Σ +)→ OH( χ 2 Π)+ Br( 2 P) reaction with a variety of density functional theory methods is studied. The methods included SVWN, BLYP, B1LYP, B3LYP, B3PW9I, and B3P86. The B1LYP/6-311++G(3df, 3pd) method give the best approximate of around 2.94 kcal/mol for the classical barrier height, which is in excellent agreement with the experimental values available. This work describes our conclusions in regards to what the geometry of the transition state is. It has been argued by previous ab initio studies that the transition state is linear however, in this work density functional theory reveals not only good experimental correlation to the theoretical results but also enough evidence to clearly label the transition state for this reaction to be bent. Lowdin and Mulliken bond orders, imaginary frequencies, and calculated partition functions are used in support to our claim.