Comprehensive study of coupled-cluster singles and doubles Green function (GFCCSD) on periodic systems*

Coupled-cluster singles and doubles (CCSD) is known to reproduce electronic correlation with high accuracy. By employing the Green’s function developed within the CCSD scheme (GFCCSD), one is capable of obtaining physical quantities including energy spectrum [1]. No periodic system, however, has been treated by GFCCSD except for electron gas [2]. In this work, we have developed a code to calculate the one-particle Green’s functions of periodic systems through GFCCSD and applied it to several realistic materials. We have found that the spectral functions and the band structures well exhibit the effects of the electronic correlation. We have also examined the differences between the calculated and experimental results.

[1] M. Nooijen and J. G. Snijders, Int. J. Quantum Chem. Symp. 44(S26), 55 (1992). M. Nooijen and J. Snijders, Int. J. Quantum Chem. 48, 15 (1993).
[2] J. McClain, J. Lischner, T. Watson, D. A. Matthews, E. Ronca, S. G. Louie, T. C. Berkelbach and G. K. Chan, Phys. Rev. B 93, 235139 (2016).