Assessment of time-dependent density functional theory with the restricted excitation space approximation for excited state calculations of large systems

Hanson-Heine, Magnus W.D. and George, Michael W. and Besley, Nicholas A. (2018) Assessment of time-dependent density functional theory with the restricted excitation space approximation for excited state calculations of large systems. Molecular Physics, 116 (11). pp. 1452-1459. ISSN 1362-3028

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Abstract

The restricted excitation subspace approximation is explored as a basis to reduce the memory storage required in linear response time-dependent density functional theory (TDDFT) calculations within the Tamm-Dancoff approximation. It is shown that excluding the core orbitals and up to 70% of the virtual orbitals in the construction of the excitation subspace does not result in significant changes in computed UV/vis spectra for large molecules. The reduced size of the excitation subspace greatly reduces the size of the subspace vectors that need to be stored when using the Davidson procedure to determine the eigenvalues of the TDDFT equations. Furthermore, additional screening of the two-electron integrals in combination with a reduction in the size of the numerical integration grid used in the TDDFT calculation leads to significant computational savings. The use of these approximations represents a simple approach to extend TDDFT to the study of large systems and make the calculations increasingly tractable using modest computing resources.

Item Type: Article
Keywords: TDDFT; large systems; restricted subspace approximation
Schools/Departments: University of Nottingham Ningbo China > Faculty of Science and Engineering > Department of Chemical and Environmental Engineering
University of Nottingham, UK > Faculty of Science > School of Chemistry
Identification Number: https://doi.org/10.1080/00268976.2018.1430388
Depositing User: Eprints, Support
Date Deposited: 19 Jan 2018 15:10
Last Modified: 01 May 2018 15:48
URI: http://eprints.nottingham.ac.uk/id/eprint/49206

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