A New Improvement And Application Of Gutzwiller Method

The density function theory(DFT)successfully calculates ground state properties and band structures of many materials.However,single particle approximation fails to describe electron behavior in strongly correlated materials.Several schemes for these materials have been proposed,including LDA+U,LDA+DMFT,and LDA+Gutzwiller.LDA+Gutzwiller has been applied to strongly correlated system model studies and many strongly correlated materials.It also requires much less calculation than the LDA+DMFT scheme.However,convergence near the transition point is difficult.For materials with either large Coulomb interaction or bands near the Fermi level,convergence is particularly difficult.In this paper,we present a novel application of the Gutzwiller method by combining it with Newtons method and golden section search.Our hybrid method dramatically improves convergence.In order to help people understand this method,read and understand the code,we give detailed description of all the equations used in Gutzwiller code,and equations in Gutzwiller+Newton method,and we give a brief description of the structure of our code.In order to calculate correlated materials,we propose implementation of the LDA+Gutzwiller method combined with Newtons method.Applying Newtons method with golden section search and other improvements for the self-consistence process,efficiency and convergence of calculation are improved.We compare behavior of the previous linear mix method and this Newtons method.This combined application dramatically improved self-consistent loop efficiency,and converges cases previously cannot converged.We have applied our code to study the electronic structure of several typical strong correlated materials,including SrV O3,LaCoO3 and La2O3Fe2Se2.Our results fit quite well with previous studies.