Optimized multi-site local orbitals in the large-scale DFT program CONQUEST. Issue 47 (9th April 2015)

• Record Type: Journal Article
• Authors: Nakata, Ayako; Bowler, David R.; Miyazaki, Tsuyoshi
• Is Part Of: Physical chemistry chemical physics. Volume 17:Issue 47(2015)
• Page Start: 31427
• Page End: 31433
• Publication Date: 2015-04-09
• Subjects: Chemistry, Physical and theoretical -- Periodicals; 541.3
• DOI: 10.1039/c5cp00934k
• Languages: English
• ISSNs: 1463-9076

Abstract

Abstract : Newly introduced numerical optimization of multi-site support functions in the linear-scaling DFT code CONQUEST improves the accuracy and stability of the support functions with small cutoffs. Abstract : We introduce numerical optimization of multi-site support functions in the linear-scaling DFT code CONQUEST. Multi-site support functions, which are linear combinations of pseudo-atomic orbitals on a target atom and those neighbours within a cutoff, have been recently proposed to reduce the number of support functions to the minimal basis while keeping the accuracy of a large basis [ J. Chem. Theory Comput., 2014, 10, 4813]. The coefficients were determined by using the local filter diagonalization (LFD) method [ Phys. Rev. B: Condens. Matter Mater. Phys., 2009, 80, 205104]. We analyse the effect of numerical optimization of the coefficients produced by the LFD method. Tests on crystalline silicon, a benzene molecule and hydrated DNA systems show that the optimization improves the accuracy of the multi-site support functions with small cutoffs. It is also confirmed that the optimization guarantees the variational energy minimizations with multi-site support functions.