Equilibrium Spectral Functions from Finite-temperature Real-Time One-particle Green's Functions for Realistic Systems

Equilibrium spectral functions are of central importance in condensed matter physics, providing information about the states available to the electrons in a system. Real-frequency spectral functions are typically calculated by analytically continuing imaginary-time equilibrium Green's functions. In this work, we obtain finite-temperature real-time self-consistent Green's Functions within the second-order self-energy approximation by solving the equilibrium Kadanoff-Baym equations. We then obtain real-frequency spectral functions from the Fourier transform of this data. Results for molecular systems are discussed and compared to current state of the art calculations.