Optimized local basis set for Kohn-Sham density functional theory

摘要

We develop a technique for generating a set of optimized local basisfunctions to solve models in the Kohn-Sham density functional theory for bothinsulating and metallic systems. The optimized local basis functions areobtained by solving a minimization problem in an admissible set determined by alarge number of primitive basis functions. Using the optimized local basis set,the electron energy and the atomic force can be calculated accurately with asmall number of basis functions. The Pulay force is systematically controlledand is not required to be calculated, which makes the optimized local basis setan ideal tool for ab initio molecular dynamics and structure optimization. Wealso propose a preconditioned Newton-GMRES method to obtain the optimized localbasis functions in practice. The optimized local basis set is able to achievehigh accuracy with a small number of basis functions per atom when applied to aone dimensional model problem.