Implementation of the multireference Brillouin-Wigner and Mukherjee's coupled cluster methods with non-iterative triple excitations utilizing reference-level parallelism

0384505 - ÚFCH JH 2013 RIV US eng J - Článek v odborném periodiku
Bhaskaran-Nair, Kiran - Brabec, Jiří - Apra, E. - van Dam, H. J. J. - Pittner, Jiří
Implementation of the multireference Brillouin-Wigner and Mukherjee's coupled cluster methods with non-iterative triple excitations utilizing reference-level parallelism.
Journal of Chemical Physics. Roč. 137, č. 9 (2012), 094112. ISSN 0021-9606. E-ISSN 1089-7690
Grant CEP: GA ČR GAP208/11/2222
Institucionální podpora: RVO:61388955
Klíčová slova: multireference methods * molecular applications * Brillouin-Wogner
Kód oboru RIV: CF - Fyzikální chemie a teoretická chemie
Impakt faktor: 3.164, rok: 2012

In this paper we discuss the performance of the non-iterative state-specific multireference coupled cluster (SS-MRCC) methods accounting for the effect of triply excited cluster amplitudes. The corrections to the Brillouin-Wigner and Mukherjee's MRCC models based on the manifold of singly and doubly excited cluster amplitudes (BW-MRCCSD and Mk-MRCCSD, respectively) are tested and compared with exact full configuration interaction results for small systems (H2O, N-2, and Be-3). For the larger systems (naphthyne isomers) the BW-MRCC and Mk-MRCC methods with iterative singles, doubles, and non-iterative triples (BW-MRCCSD(T) and Mk-MRCCSD(T)) are compared against the results obtained with single reference coupled cluster methods. We also report on the parallel performance of the non-iterative implementations based on the use of processor groups.
Trvalý link: http://hdl.handle.net/11104/0214132