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Correlated polarization propagator calculations of static polarizabilities
Author(s) -
Sauer Stephan P. A.,
Oddershede Jens
Publication year - 1994
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.560500502
Subject(s) - polarizability , chemistry , propagator , degenerate energy levels , electronic correlation , dipole , ground state , perturbation theory (quantum mechanics) , computational chemistry , atomic physics , molecule , molecular physics , physics , quantum mechanics , organic chemistry
We present a systematic comparison of the correlation contribution at the level of the second‐order polarization propagator approximation ( SOPPA ) and MP 2 to the static dipole polarizability of (1) Be, BeH − , BH, CH + , MgH − , AIH, SiH + , and GeH + ; (2) BH 3 , CH 4 , NH 3 , H 2 O, HF, BF, and F 2 ; and (3) N 2 , CO, CN − , HCN, C 2 H 2 , and HCHO . Fairly extended basis sets were used in the calculations. We find that the agreement with experimental values is improved in SOPPA and MP .2 over the results at the SCF level. The signs and magnitudes of the correlation contribution in SOPPA are similar to those obtained in analytical derivative MP 2 calculations. However, it is not possible to say, in general, which method gives the largest correlation contribution or the best agreement with experiment, nor is it possible to make a priori prediction of the sign of the correlation contribution. For the first group of molecules, which have a quasi‐degenerate ground state, additional CCDPPA and CCSDPPA calculations were performed and compared with polarizabilities obtained as analytical/numerical derivatives of the CCD and CCSD energies. The CCSDPPA results were found to be in better agreement with other calculations than were the SOPPA results, demonstrating the necessity of using methods based on infinite‐order perturbation theory for these systems. © 1994 John Wiley & Sons, Inc.