Reduced Variational Space

Stevens WJ, Fink WH (1987) Frozen fragment reduced variational space analysis of hydrogen bonding interactions. Application to water dimer. Chem Phys Lett 139 15... 

A reduced variational space method, related to the KM procedure, has been developed in which the orbitals of one fragment are optimized in the field of the frozen orbitals of its partner. Truncation of the variational space by deletion of unoccupied orbitals of one partner or the other is the pathway to evaluation of polarization, charge-transfer, and BSSE terms. When applied to the water dimer -", the Coulomb and exchange sum dominates the interaction but charge transfer and polarization terms are needed for proper angular dependence. 

Methane is the most weakly binding alkane yet is the most important for conversion chemistry. A calculational technique (reduced variational space analysis) used by Cundari indicates that three energetic components control binding of CH4 Coulomb and exchange repulsion, polarization of CH4, and CH4 - M charge... 

Reduced variational space Reduced variational space... 

EL-HAV = Eisenschitz, London-Hirschfelder, Amos, Van der Avoird FORS = fully optimized reaction space IMPT = intermolecular perturbation theory JS = Jeziorski-Kolos LCD = localized charge distribution MK = Morokuma-Ki-taura MS-MA = Murrell. Shaw-Musher, Amos RS-PT = Rayleigh-Schrodinger perturbation theory RVS = reduced variational space SA = symmetry-adapted perturbation theory SNOPT = symmetric non-orthogonal perturbation theory SRS = symmetrized Rayleigh-Schrddinger. 

The reduced variational space (RVS) method i.s due to Stevens and Fink and is essentially identical to the constrained space orbital variations method of Bagus et al. The... 

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