[SY-E4] Symposium E-4

[SY-E4] The local-orbital construction of strongly correlated electrons based on the PAW method

^○Yu Liu^1,2, Xingyu Gao^1,2, Jianzhou Zhao³, Haifeng Song^1,2 (1.Institute of Applied Physics and Computational Mathematics, China, 2.CAEP Software Center for High Performance Numerical Simulation, China, 3.Southwest University of Science and Technology, China)

The effects of electron strong correlation, spin-orbit coupling and multi-configuration bring out challenges in the first principle studies of some nuclear materials and rare-earth materials. Density functional theory (DFT), however, cannot properly describe their electronic structures. For this reason, people have developed Hubbard model based post-DFT method (DFT+X) to correct the strong correlation effect. The coupler that connects the DFT and X still requires more intensive research. In this report, we will present the most recent progress on the DFT+X coupler and its realization in the projector augmented wave (PAW) method under the infrastructure of CESSP code. Firstly, there are three major schemes, namely P0, P1 and P2, to construct the local orbitals of the strong correlated electrons. Prof. Haule from Rutgers University demonstrate the advantages of P2 scheme under the linear augmented plane wave (LAPW) method. However, we are going to show that under the PAW method, P2 is more appropriate for systems with d electrons while P1 is more appropriate for systems with f electrons. Secondly, we realize the correction of spin-orbit coupling and crystal field splitting to the local orbitals, which improves the convergence and accuracy of the DFT+X calculations. We further test our code in the typical strong correlated materials SrVO₃ and Ce.