Global potential energy hypersurface for dynamical studies of energy transfer in HF--HF collisions

Journal Article · Wed Jul 15 04:00:00 EDT 1987 · J. Chem. Phys.; (United States)

DOI:https://doi.org/10.1063/1.453252· OSTI ID:6495196

Redmon, M J; Binkley, J S

The interaction energy of two HF molecules at 1332 individual points has been calculated with Moeller--Plesset (many--body) perturbation theory at the MP4-SDTQ level using a 6-311G** basis set. 293 of the points correspond to stretching of one HF molecule from its equilibrium geometry. No attempt was made to use a sufficiently fine grid to accurately describe the well region corresponding to hydrogen bonding. However, the location and minimum energy are consistent with experiment and other accurate theoretical results. An extensive global fit (rms error of 1 kcal/mol) is reported of 1319 points (below 10 eV of potential energy) using a modified London potential with corrections obtained using polynomials through four-body interactions. A model electrostatic potential represents the long-range interaction. In addition, the use of an expansion in products of three Legendre functions is discussed. It is shown that the latter approach, although accurately fitting the ab initio data, has difficulties interpolating in regions of the surface exhibiting diverse magnitudes of potential energy, and therefore must be used with caution. This surface should be useful for studies of T--V--R processes in this system.

• Research Organization: Chemical Dynamics, Columbus, Ohio 43220
• OSTI ID: 6495196
• Journal Information: J. Chem. Phys.; (United States), Journal Name: J. Chem. Phys.; (United States) Vol. 87:2; ISSN JCPSA
• Country of Publication: United States
• Language: English

Related Subjects

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74 ATOMIC AND MOLECULAR PHYSICS
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ENERGY TRANSFER
HYDROFLUORIC ACID
HYDROGEN COMPOUNDS
INORGANIC ACIDS
PERTURBATION THEORY
POTENTIAL ENERGY