Feshbach-Fano Approach for Calculation of Auger Decay Rates Using Equation-of-Motion Coupled-Cluster Wave Functions: Numerical Examples and Benchmarks
This manuscript is concerned with numerical illustration of the theoretical framework for computing Auger decay rates based on the Feshbach-Fano approach and the equation-of-motion coupled-cluster ansatz, augmented with core-valence separation scheme. We consider two analytical approximations to the continuum orbital describing the Auger electron: a plane wave and a Coulomb wave with an effective charge. Theoretical Auger electron spectra are presented for benchmark systems (Ne, H2O, CH4 and CO2) and compared with available experimental spectra. Results of the presented benchmark tests show that the proposed computational scheme provides reliable ab initio preditions of the Auger spectra. The reliability, cost-efficiency, and robust computational setup of this methodology offer advantages in applications to a large variety of systems.