2025/02/07 by Rafael Grande, Del Grande, Rafael R., David A. Strubbe +1 · 1 citation
Computer Science · Physics and Astronomy · #Cold Atom Physics and Bose-Einstein Condensates #FOS: Physical sciences #Materials Science (cond-mat.mtrl-sci) #Quantum Information and Cryptography #Quantum optics and atomic interactions
paper · pdf · doi:10.48550/arxiv.2502.05144
openalex publication_date 2025/02/07 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/31
Ab initio techniques for studying the optical and vibrational properties of materials are well-established, but only a few recent studies have focused on the interaction between excitons and atomic vibrations. In this paper, we revisit the excited state forces method, based on GW/BSE and DFPT calculations and provide a practical implementation and straightforward workflow. We fixed issues from Ismail-Beigi and Louie's implementation in \textcolorbluePhys. Rev. Lett. 90, 076401 (2003) and use an approximation for GW-level electron-phonon coefficients that improves our calculations accuracy. We explore its technical aspects, including convergence and the quality of approximations used for CO molecule, LiF and monolayer MoS2. We successfully apply this method to investigate diverse kinds of self-trapped excitons in LiF, including polaronic excitons, discuss excited state relaxation strategies and project excited state forces in phonon displacement to explore exciton-phonon interactions. Our results provide the tools to study exciton-phonon related phenomena in molecules in materials, including coherent phonon generation, such as resonant Raman, self-trapped excitons and excitonic insulators.