제일원리에 기반한 강상관 전자계의 전자구조 계산: DFT+U와 DFT+DMFT 방법론

Abstract

In this article, we briefly discuss DFT+U and +DMFT in a comparative way and from a practical point of view. Both methods share many common features; not only the basic idea but the important technical issues such as determination of interaction parameters and defining double-counting functionals. We first introduce the common basic idea of two methods with DFT+U as an example, and discuss how the formal differences can lead to different material characteristics in the result. The characteristic features of DFT+DMFT as a ‘dymanical’ approximation are then presented and discussed in comparison with DFT+U.