ISSN:
0192-8651
Keywords:
natural resonance theory
;
resonance theory
;
natural bond orbitals
;
Chemistry
;
Theoretical, Physical and Computational Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Computer Science
Notes:
We present a new quantum-mechanical resonance theory based on the first-order reduced density matrix and its representation in terms of natural bond orbitals (NBOs). This “natural” resonance theory (NRT) departs in important respects from the classical Pauling-Wheland formulation, yet it leads to quantitative resonance weights that are in qualitative accord with conventional resonance theory and chemical intuition. The NRT variational functional leads to an optimal resonance-weighted approximation to the full density matrix, combining the “single reference” limit of weak delocalization (incorporating diagonal population changes only) with the full “multireference” limit of strong delocalization (incorporating off-diagonal couplings between resonance structures. The NRT variational functional yields an error measure that serves as an intrinsic criterion of accuracy of the resonance-theoretic description. The NRT program structure, algorithms, and numerical characteristics are described in supplementary material, and detailed chemical applications are presented in two companion papers. © 1998 John Wiley & Sons, Inc. J Comput Chem 19: 593-609, 1998
Additional Material:
1 Tab.
Type of Medium:
Electronic Resource
