Optimized multi-site local orbitals in the large-scale DFT program CONQUEST
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, 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.
Cite
@article{arxiv.1502.05588,
title = {Optimized multi-site local orbitals in the large-scale DFT program CONQUEST},
author = {Ayako Nakata and David R. Bowler and Tsuyoshi Miyazaki},
journal= {arXiv preprint arXiv:1502.05588},
year = {2016}
}
Comments
25 pages, 3 figures, submitted to Phys. Chem. Chem. Phys