Harris-type van der Waals density functional scheme
Artikel i vetenskaplig tidskrift, 2013

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.

Författare

Kristian Berland

Chalmers, Teknisk fysik, Elektronikmaterial och system

Elisa Londero

Chalmers, Mikroteknologi och nanovetenskap (MC2), Kvantkomponentfysik

Elsebeth Schröder

Chalmers, Mikroteknologi och nanovetenskap (MC2), Kvantkomponentfysik

Per Hyldgaard

Chalmers, Teknisk fysik, Elektronikmaterial och system

Physical Review B - Condensed Matter and Materials Physics

1098-0121 (ISSN)

Vol. 88 4

Styrkeområden

Nanovetenskap och nanoteknik

Materialvetenskap

Fundament

Grundläggande vetenskaper

Infrastruktur

C3SE (Chalmers Centre for Computational Science and Engineering)

Ämneskategorier

Den kondenserade materiens fysik

DOI

10.1103/PhysRevB.88.045431

Mer information

Skapat

2017-10-07