Linear-scaling formation of Kohn-Sham Hamiltonian: Application to the calculation of excitation energies and polarizabilities of large molecular systems
2004 (English)In: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 121, no 7, 2915-2931 p.Article in journal (Refereed) Published
We present calculations of excitation energies and polarizabilities in large molecular systems at the local-density and generalized-gradient approximation levels of density-functional theory (DFT). Our results are obtained using a linear-scaling DFT implementation in the program system DALTON for the formation of the Kohn-Sham Hamiltonian. For the Coulomb contribution, we introduce a modification of the fast multipole method to calculations over Gaussian charge distributions. It affords a simpler implementation than the original continuous fast multipole method by partitioning the electrostatic Coulomb interactions into classical and nonclassical terms which are explicitly evaluated by linear-scaling multipole techniques and a modified two-electron integral code, respectively. As an illustration of the code, we have studied the singlet and triplet excitation energies as well as the static and dynamic polarizabilities of polyethylenes, polyenes, polyynes, and graphite sheets with an emphasis on the trends observed with system size.
Place, publisher, year, edition, pages
2004. Vol. 121, no 7, 2915-2931 p.
density-functional theory, fast multipole method, exchange-correlation functionals, numerical-integration, efficient implementation, electron-densities, matrix search, algorithm, gradient, diagonalization
IdentifiersURN: urn:nbn:se:kth:diva-23614DOI: 10.1063/1.1771639ISI: 000222995300009ScopusID: 2-s2.0-4344578234OAI: oai:DiVA.org:kth-23614DiVA: diva2:342313
QC 20100525 QC 201109232010-08-102010-08-102011-09-23Bibliographically approved