The Au(I)Au(I) interaction: Hartree-Fock and Møller-Plesset second-order perturbation theory calculations on [Se5Au2]2− and [Se6Au2]2− complexes

1997 ◽  
Vol 277 (1-3) ◽  
pp. 215-222 ◽  
Author(s):  
Daniel E. Bacelo ◽  
S.D. Huang ◽  
Yasuyuki Ishikawa
Keyword(s):  
Perturbation Theory ◽  
Second Order ◽  
Order Perturbation ◽  
Order Perturbation Theory ◽  
Hartree Fock ◽  
Moller Plesset ◽  
Second Order Perturbation Theory

Microsolvation of methylmercury: structures, energies, bonding and NMR constants (199Hg,13C and17O)

2016 ◽  
Vol 18 (3) ◽  
pp. 1537-1550 ◽  
Author(s):  
Edison Flórez ◽  
Alejandro F. Maldonado ◽  
Gustavo A. Aucar ◽  
Jorge David ◽  
Albeiro Restrepo
Keyword(s):  
Perturbation Theory ◽  
Second Order ◽  
Order Perturbation ◽  
Order Perturbation Theory ◽  
Water Molecules ◽  
Interaction Energies ◽  
Hartree Fock ◽  
Mp2 Calculations ◽  
Equilibrium Geometries ◽  
Second Order Perturbation Theory

Hartree–Fock (HF) and second order perturbation theory (MP2) calculations within the scalar and full relativistic frames were carried out in order to determine the equilibrium geometries and interaction energies between cationic methylmercury (CH3Hg+) and up to three water molecules.

The use of special coordinate axes in direct and semi-direct implementations of second-order perturbation theory, including the derivation of a horizontal recurrence relation

1992 ◽  
Vol 70 (2) ◽  
pp. 416-420 ◽  
Author(s):  
Tracy P. Hamilton ◽  
Henry F. Schaefer III
Keyword(s):  
Perturbation Theory ◽  
Recurrence Relation ◽  
Reference Frames ◽  
Integral Transformation ◽  
Second Order ◽  
Order Perturbation ◽  
Order Perturbation Theory ◽  
Moller Plesset ◽  
Cartesian Coordinate ◽  
Second Order Perturbation Theory

A horizontal recurrence relation (HRR) is derived which may be used in the generation of two-electron repulsion integrals (ERIs). Also, special Cartesian coordinate axes may be used to reduce the number of intermediate terms. Heretofore, the use of local axis systems entailed rotations every time a shell quadruple of ERIs was computed. Recently, we pointed out the possibility of postponing the transformation using choices of Cartesian reference frames based on nuclear positions. In our pilot implementation of direct and semi-direct Møller–Plesset second-order perturbation theory (MP2) we construct the integrals in local coordinate systems and perform the back-transformation in the middle of the AO to MO integral transformation, rather than rotating the ERIs after the computation of each shell quadruple. The efficacy of this approach depends on whether the gains in ERI computation are greater than the losses incurred in transformation. Preliminary CPU profiles indicate that the increased time spent in rotating axes is quite small. Keywords: horizontal recurrence relation, second-order perturbation theory.

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