ISSN:
0020-7608
Keywords:
Computational Chemistry and Molecular Modeling
;
Atomic, Molecular and Optical Physics
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
A formalism has been developed to treat hydrogen-bonded A - H…B systems within the CNDO/2 and the MINDO/3 methodologies. In this formalism the interactions are divided into three distinct classes; those between (a) two hydrogen-bonded atoms, (b) one hydrogen-bonded and non-hydrogen-bonded atom, and (c) two non-hydrogen-bonded atoms. The last class of interactions is treated solely by the existing CNDO/2 or MINDO/3 method. For A -H…B systems, the core resonance integrals are individually parametrized depending upon the class of the interaction. Three types of A - H…B systems have been thus far parametrized. Nine hydrogen-bonded dimers have been studied using the new formalism and the current CNDO/2 and the MINDO/3 methods. MINDO/3 predicts very large interatomic (A -B) distances for the equilibrium geometry, and relatively small stabilization values for the hydrogen-bond energies. CNDO/2 predicts the reverse. The new formalism for both CNDO/2 and MINDO/3 predicts accurate geometries as well as energies for all nine dimers. The new formalisms are called CNDO/2H and MINDO/3H. A general discussion of the nature of hydrogen bonding as exhibited by CNDO/2H and MINDO/3H is presented.
Additional Material:
12 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/qua.560220605
