Benchmark calculations of the complete configuration-interaction limit of Born–Oppenheimer diagonal corrections to the saddle points of isotopomers of the H + H2 reaction

June 8, 2005

Journal Article

Benchmark calculations of the complete configuration-interaction limit of Born–Oppenheimer diagonal corrections to the saddle points of isotopomers of the H + H2 reaction

Abstract

We present a detailed ab initio study of the effect that the Born–Oppenheimer diagonal correction (BODC) has on the saddle point properties of the H3 system and its isotopomers. Benchmark values are presented that are estimated to be within 0.1 cm–1 of the complete configuration interaction limit. We consider the basis set and correlation treatment requirements for accurate BODC calculations, and both are observed to be more favorable than for the Born–Oppenheimer energies. The BODC raises the H + H2 barrier height by 0.1532 kcal/mol and slightly narrows the barrier—with the imaginary frequency increasing by ~2%.

Revised: April 13, 2007 | Published: June 8, 2005

Citation

Mielke S.L., D. Schwenke, and K.A. Peterson. 2005. Benchmark calculations of the complete configuration-interaction limit of Born–Oppenheimer diagonal corrections to the saddle points of isotopomers of the H + H2 reaction. Journal of Chemical Physics 122. PNNL-SA-44669.