Robust Analytic-Continuation Approach to Many-Body GW Calculations

Ivan Duchemin (1) , Xavier Blase (2)

1 LSIM - Laboratory of Atomistic Simulation
2 NEEL - TMC - Théorie de la Matière Condensée

The analytic continuation of the GW self-energy from the imaginary to the real energy axis is a central difficulty for approaches exploiting the favourable properties of response functions at imaginary frequencies. Within a scheme merging contour-deformation and analytic-continuation techniques, we show on the basis of extensive calculations for large molecular sets that it is preferable to perform an analytic continuation of the dynamically screened Coulomb potential W rather than the much more structured self-energy operator. The case of states lying far away from the gap, including core states, is addressed by generalizing the analytic continuation scheme, accounting further for quasiparticle lifetimes.

Domaines: Chimie théorique et/ou physique; Matière Condensée [cond-mat]

Ivan Duchemin, Xavier Blase. Robust Analytic-Continuation Approach to Many-Body GW Calculations. Journal of Chemical Theory and Computation, 2020, 16 (3), pp.1742-1756. ⟨10.1021/acs.jctc.9b01235⟩. ⟨hal-02766493⟩