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 Article · Wed Jun 08 04:00:00 EDT 2005 · Journal of Chemical Physics, 122:Art. No. 224313

DOI:https://doi.org/10.1063/1.1917838· OSTI ID:902410

Mielke, Steven L; Schwenke, David; Peterson, Kirk A

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%.

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (US)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 902410
• Report Number(s): PNNL-SA-44669; KC0301020
• Journal Information: Journal of Chemical Physics, 122:Art. No. 224313, Journal Name: Journal of Chemical Physics, 122:Art. No. 224313 Vol. 122; ISSN JCPSA6; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
BENCHMARKS
BORN-OPPENHEIMER APPROXIMATION
CHEMICAL REACTIONS
CONFIGURATION INTERACTION
CORRECTIONS
HYDROGEN
SADDLE-POINT METHOD
isotopomers