Coupled-cluster theory is well known to describe dynamical electron correlation at a very high level. In the past 8-10 years, the theory has been extended to not only describe ground and excited electronic states but also correlated many-electron dynamics driven by laser fields. Researchers at the Hylleraas Centre in Oslo have made foundational contributions to this development.
Continuing our efforts in this direction, this paper proposes a theoretical framework that allows us to interpret complicated laser-driven quantum dynamics in chemically meaningful terms – i.e., in terms of transitions between orbitals or between specific electron configurations. Importantly, the chemically meaningfull interpretation is extracted directly from the simulation data with negligible computational overhead.
The paper illustrates the power of the proposed methodology through numerical simulations of linear absorption spectra in both valence and core spectral regions, induced stimulated X-ray Raman scattering, and optical pump – X-ray probe spectroscopy.
The work is a collaboration between Håkon Emil Kristiansen and Thomas Bondo Pedersen at the Hylleraas Centre in Oslo, Ben Peyton at Michigan State University, and Aparna Krishnan and Daniel Crawford at Virginia Tech, and is a generalization of our recent work on ground-state configuration weights to the time-dependent regime.
Published: 13th August 2026: