Molecular mechanics parameters for fluorine-substituted methanes from ab initio quantum calculations

Journal Article · Thu Aug 10 04:00:00 EDT 1995 · Journal of Physical Chemistry

DOI:https://doi.org/10.1021/j100032a029· OSTI ID:111202

Palmer, B J; Anchell, J L ^[1]

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1. Pacific Northwest Lab., Richland, WA (United States)

Molecular mechanics parameters for the homologous series of fluorine-substituted methanes, CH{sub x}F{sub 4-o} are derived from ab initio Hartree-Fock surfaces. Ab initio intermolecular potential energy surfaces are calculated using a 6-31+G basis set and include correlation using second-order Moller-Plesset perturbation theory. A least squares fit of the ab initio surface to a standard molecular mechanics potential function, including Lennard-Jones interactions plus partial charges, is then performed. The thermodynamic properties of the resulting molecular mechanics potential are calculated using conventional molecular dynamics simulations and compared to experimental results. Additional fine-tuning of the molecular mechanics potential is then performed to optimize the agreement with experimental results. The effect of including high-energy configurations in the fit is systematically investigated. 28 refs., 12 figs., 14 tabs.

• Sponsoring Organization: USDOE
• DOE Contract Number: AC06-76RL01830
• OSTI ID: 111202
• Journal Information: Journal of Physical Chemistry, Journal Name: Journal of Physical Chemistry Journal Issue: 32 Vol. 99; ISSN JPCHAX; ISSN 0022-3654
• Country of Publication: United States
• Language: English

Related Subjects

40 CHEMISTRY
66 PHYSICS
99 GENERAL AND MISCELLANEOUS
CALCULATION METHODS
FLUORINATED ALIPHATIC HYDROCARBONS
HARTREE-FOCK METHOD
INTERMOLECULAR FORCES
LENNARD-JONES POTENTIAL
METHANE
MOLECULAR MODELS
POTENTIAL ENERGY
QUANTUM ELECTRODYNAMICS
THEORETICAL DATA