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Elongation method with cutoff technique for linear SCF scaling
Author(s) -
Korchowiec Jacek,
Gu Feng Long,
Imamura Akira,
Kirtman Bernard,
Aoki Yuriko
Publication year - 2005
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.20448
Subject(s) - cutoff , computation , scaling , hartree–fock method , basis set , chemistry , basis (linear algebra) , coupling (piping) , conformational isomerism , cutoff frequency , physics , elongation , fock space , electronic correlation , statistical physics , quantum mechanics , computational chemistry , mathematics , electron , molecule , density functional theory , materials science , algorithm , geometry , optics , metallurgy , ultimate tensile strength
The elongation method uses the concept of locality and works in a regionally localized molecular orbital basis set. In this method the system is partitioned into several frozen fragments and an active one. If the coupling between a given frozen fragment and the active space is small enough, one can develop a cutoff scheme for effectively discarding the former in all further calculations. At the Hartree–Fock level many two‐electron integrals are thereby eliminated, leading to a reduction in self‐consistent field computation time. In test calculations on four polyglycine conformers, with an appropriate default threshold for coupling, the cutoff error is very small and/or comparable to that of a normal elongation calculation. On the other hand, the computation time for 20 residues is a factor of 5 less than that of a normal Hartree–Fock treatment and scales linearly (or even sublinearly) with the number of residues. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005