2022/12/15 by Tenkila, G., Chand, V., Miyagi, T. +4
#Atomic Physics (physics.atom-ph) #FOS: Physical sciences #Nuclear Experiment (nucl-ex) #Nuclear Theory (nucl-th)
paper · doi:10.48550/arxiv.2212.08188
Precise theoretical calculations of open-shell atomic systems are critical for extracting fundamental physics parameters from precision experiments. Here we present proof-of-principle calculations illustrating the effectiveness of the valence-space formulation of the ab initio in-medium similarity renormalization group, widely used in nuclear theory, as a new ab initio method for atomic systems. We adapt this approach to study properties of closed- and open-shell many-electron systems from helium to calcium. Ground-state energies, excitation spectra, and ionization energies are obtained for selected atoms, and reasonable agreement is found with benchmark coupled-cluster and many-body perturbation theory calculations, where available.