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Hydrogen bonding: Methodology and applications to complexes of HF and HCl with HCN and CH 3 CN
Author(s) -
Del Bene Janet E.
Publication year - 1992
Publication title -
international journal of quantum chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.484
H-Index - 105
eISSN - 1097-461X
pISSN - 0020-7608
DOI - 10.1002/qua.560440848
Subject(s) - counterpoise , chemistry , basis set , binding energy , valence (chemistry) , hydrogen bond , atomic physics , computational chemistry , molecular physics , density functional theory , physics , molecule , organic chemistry
A detailed investigation has been made of the methodological dependence of computed structures, binding energies, and some vibrational properties of selected hydrogen‐bonded complexes. Structures and vibrational frequencies have been computed using four different levels of theory: HF /6‐31G( d ), HF /6‐31+G( d, p ), MP 2/6‐31G( d ), and MP 2/6‐31+G( d, p ). Correlation energy effects on computed binding energies and the basis set dependence of these energies have been evaluated using the Dunning correlation‐consistent polarized valence double‐, triple‐, and truncated quadruple‐split basis sets (cc‐pVXZ, with X = D for double, T for triple, and Q́ for truncated quadruple), and these same basis sets augmented with diffuse functions on nonhydrogen atoms (cc‐pVXZ+). The results of these studies suggest that the methodology of MBPT (4) = MP 4/cc‐pVTZ+ electronic energies without the counterpoise correction computed at MP 2/6‐31+G( d, p ) geometries is an appropriate theoretical model for investigating complexes RCN ⃛ HX, with R = H or CH 3 and X = F or Cl. This model has been applied to investigate the structures, binding energies at absolute zero, binding enthalpies at room temperature, and vibrational frequencies of these complexes. Trends are noted, and comparisons are made with available experimental data. © 1992 John Wiley & Sons, Inc.