English
 
Help Privacy Policy Disclaimer
  Advanced SearchBrowse

Item

ITEM ACTIONSEXPORT

Released

Journal Article

The resolution of identity and chain of spheres approximations for the LPNO-CCSD singles Fock term

MPS-Authors
/persons/resource/persons216815

Izsák,  Róbert
Research Department Neese, Max Planck Institute for Bioinorganic Chemistry, Max Planck Society;

/persons/resource/persons237583

Hansen,  Andreas
Research Department Neese, Max Planck Institute for Bioinorganic Chemistry, Max Planck Society;

/persons/resource/persons216825

Neese,  Frank
Research Department Neese, Max Planck Institute for Bioinorganic Chemistry, Max Planck Society;

External Resource
No external resources are shared
Fulltext (public)
There are no public fulltexts stored in PuRe
Supplementary Material (public)
There is no public supplementary material available
Citation

Izsák, R., Hansen, A., & Neese, F. (2012). The resolution of identity and chain of spheres approximations for the LPNO-CCSD singles Fock term. Molecular Physics, 110(19-20), 2413-2417. doi:10.1080/00268976.2012.687466.


Cite as: http://hdl.handle.net/21.11116/0000-0007-E5C7-6
Abstract
In the present work, the RIJCOSX approximation, developed earlier for accelerating the SCF procedure, is applied to one of the limiting factors of LPNO-CCSD calculations: the evaluation of the singles Fock term. It turns out that the introduction of RIJCOSX in the evaluation of the closed shell LPNO-CCSD singles Fock term causes errors below the microhartree limit. If the proposed procedure is also combined with RIJCOSX in SCF, then a somewhat larger error occurs, but reaction energy errors will still remain negligible. The speedup for the singles Fock term only is about 9–10 fold for the largest basis set applied. For the case of Penicillin using the def2-QZVPP basis set, a single point energy evaluation takes 2 day 16 h on a single processor leading to a total speedup of 2.6 as compared to a fully analytic calculation. Using eight processors, the same calculation takes only 14 h.