uu.seUppsala University Publications
Change search
ReferencesLink to record
Permanent link

Direct link
Integral-direct electron correlation methods
Department of Theoretical Chemistry, Lund University.ORCID iD: 0000-0001-7567-8295
1999 (English)In: Molecular Physics, ISSN 0026-8976, E-ISSN 1362-3028, Vol. 96, no 4, 719-733 p.Article in journal (Refereed) Published
Abstract [en]

Integral-direct implementations of Moller-Plesset perturbation theory up to fourth order (MP4(SDQ) without triple excitations), quadratic configuration interaction with single and double excitations (QCISD), coupled cluster (CCSD), multiconfiguration self-consistent field (MCSCF), second- and third-order multireference perturbation theory (MRPT2, MRPT3), and internally contracted multireference configuration interaction (MRCI) methods are described. All methods use the same three integral-direct kernels, namely direct calculation of Fock matrices, direct partial integral transformation, and direct evaluation of external exchange matrices. New algorithms for the latter two procedures are proposed and implemented, for which the memory requirement scales only linearly with basis set size. Test calculations with more than 500 basis functions are presented. It is demonstrated that integral prescreening can significantly reduce the scaling of the computational cost with molecular size N. For small polyglycine peptides (Gly)(n) (n = 1-4), we observe a scaling of N-3 for the direct integral transformation (formal scaling N-5), and N-4 for the direct computation of the external exchange matrices (formal scaling N-6).

Place, publisher, year, edition, pages
1999. Vol. 96, no 4, 719-733 p.
National Category
Chemical Sciences
URN: urn:nbn:se:uu:diva-143925DOI: 10.1080/002689799165576ISI: 000078821300027OAI: oai:DiVA.org:uu-143925DiVA: diva2:394391
Available from: 2011-02-02 Created: 2011-01-25 Last updated: 2015-01-08Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full text

Search in DiVA

By author/editor
Lindh, Roland
In the same journal
Molecular Physics
Chemical Sciences

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 420 hits
ReferencesLink to record
Permanent link

Direct link