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Harris-type van der Waals density functional scheme

Kristian Berland (Institutionen för mikroteknologi och nanovetenskap, Bionanosystem) ; Elisa Londero (Institutionen för mikroteknologi och nanovetenskap, Kvantkomponentfysik) ; Elsebeth Schröder (Institutionen för mikroteknologi och nanovetenskap, Kvantkomponentfysik) ; Per Hyldgaard (Institutionen för mikroteknologi och nanovetenskap, Bionanosystem)
Physical Review B (1098-0121). Vol. 88 (2013), 4,
[Artikel, refereegranskad vetenskaplig]

Biomolecular systems that involve thousands of atoms are difficult to address with standard density functional theory (DFT) calculations. With the development of sparse-matter methods such as the van der Waals density functional (vdW-DF) method [M. Dion et al., Phys. Rev. Lett. 92, 246401 (2004)], it is now possible to include the dispersive forces in DFT which are necessary to describe the cohesion and behavior of these systems. vdW-DF implementations can be as efficient as those for traditional DFT. Yet, the computational costs of self-consistently determining the electron wave functions and hence the kinetic-energy repulsion still limit the scope of sparse-matter DFT. We propose to speed up sparse-matter calculations by using the Harris scheme [J. Harris, Phys. Rev. B 31, 1770 (1985)]; that is, we propose to perform electronic relaxations only for separated fragments (molecules) and use a superposition of fragment densities as a starting point to obtain the total energy non-self-consistently. We evaluate the feasibility of this approach for an adaption of the Harris scheme for non-self-consistent vdW-DF (sfd-vdW-DF). We study four molecular dimers with varying degrees of polarity and find that the sfd scheme accurately reproduces standard non-self-consistent vdW-DF for van der Waals dominated systems but is less accurate for those dominated by polar interactions. Results for the S22 set of typical organic molecular dimers are promising.



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Denna post skapades 2013-08-22. Senast ändrad 2015-12-17.
CPL Pubid: 182044

 

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Institutioner (Chalmers)

Institutionen för mikroteknologi och nanovetenskap, Bionanosystem (2007-2015)
Institutionen för mikroteknologi och nanovetenskap, Kvantkomponentfysik

Ämnesområden

Materialvetenskap
Nanovetenskap och nanoteknik
Den kondenserade materiens fysik

Chalmers infrastruktur

C3SE/SNIC (Chalmers Centre for Computational Science and Engineering)