ISSN:
0020-7608
Keywords:
density functional theory
;
exchange-correlation potentials
;
grids
;
linear scaling methods
;
divide-and-conquer
;
Chemistry
;
Theoretical, Physical and Computational Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The conventional linear combination of Gaussian-type orbitals (LCGTO) density functional (DF) method fits the exchange-correlation (XC) potentials and energy density within an auxiliary basis. The benefits of this approach versus straightforward numerical quadrature of the XC terms will be discussed. However, the conventional fitting procedure scales cubically with system size and is therefore ill-suited for applications on very large systems. A divide-and-conquer (DAC) approach to the fits of the XC terms has been developed and implemented within the DeFT DF software package. This DAC procedure will be outlined, and the results and timings of benchmark 6-31G** calculations on extended glycine polypeptides will be presented. Other changes made to DeFT's XC subroutines, necessary to achieve near-linear scaling, will also be discussed. DeFT's grids have also been refined to achieve greater precision, and a scheme using fewer points for fitting procedures and more points for numerical integrations is presented. Through our preliminary efforts, we have achieved scalings in the XC modules no worse than N1.4 (N is the number of atoms) for peptides that range in size up to 83 atoms. © 1998 John Wiley & Sons, Inc. Int J Quant Chem 69: 405-421, 1998
Additional Material:
2 Ill.
Type of Medium:
Electronic Resource
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