Efficient evaluation of exchange integrals by means of Fourier transform of the 1/r operator and its numerical quadrature

0427606 - ÚFCH JH 2015 RIV DE eng J - Journal Article
Čársky, Petr - Čurík, Roman
Efficient evaluation of exchange integrals by means of Fourier transform of the 1/r operator and its numerical quadrature.
Theoretical Chemistry Accounts. Roč. 133, č. 4 (2014), s. 1466. ISSN 1432-881X. E-ISSN 1432-2234
R&D Projects: GA ČR GAP203/12/0665; GA ČR GAP208/11/0452; GA ČR GAP208/11/2222; GA MŠMT LD14088
Institutional support: RVO:61388955
Keywords : electron scattering * exchange energy * plane-wave basis
Subject RIV: CF - Physical ; Theoretical Chemistry
Impact factor: 2.233, year: 2014

In the present work, we propose an approach to factorize the non-local exchange kernel into a sum of separable terms. We exploit a discretized Fourier transform of the 1/r operator, and we devise a method that allows us to employ a manageable number of plane waves in the Fourier expansion while still keeping necessary accuracy. Resulting formulas are amenable for efficient evaluation on graphics processing units (GPU) devices. We discuss the GPU implementation for two-electron repulsion integrals of the (gk|gk) type in the hybrid Gaussian and plane-wave basis. Accuracy and speedups are demonstrated for several practical calculations of electron scattering by cyclopropane, benzene, and adamantane molecules. By that, we want to show that evaluation of (gk|gk) integrals may cease to be a bottleneck in electron scattering calculations. A message to quantum chemists is that the combination of the integral fragmentation and the use of GPU units is a general tool which may improve performance of computational methods of different types.
Permanent Link: http://hdl.handle.net/11104/0233128