Computing linear optical spectra of molecules in complex environments on Graphics Processing Units using molecular dynamics simulations and tensor-network approaches

• DOI: 10.48550/arxiv.2406.17994
• Publication Date: 2024-06-25
• Authors: Evan Lambertson; Dayana Bashirova; Kye E. Hunter; Benhardt Hansen; Tim J. Zuehlsdorff
• Keywords: Dynamics

We outline a computational workflow to model linear optical spectra of molecules in complex environments the presence nonadiabatic effects. The approach relies on computing excitation energy and transition dipole fluctuations along molecular dynamics (MD) trajectories, treating environmental degrees freedom same footing. Spectra are then generated following two distinct strategies: In recently developed Gaussian Non-Condon Theory (GNCT), response functions computed terms independent adiabatic excited states, with non-Condon effects described through spectral densities fluctuations. For strongly coupled we instead parameterize vibronic coupling (LVC) Hamiltonian directly from diabatic couplings MD trajectory. spectrum is calculated using powerful numerically exact tensor-network approaches. Both electronic structure calculations sample system quantum simulations methods carried out graphics processing units (GPUs), enabling rapid condensed phase systems. showcase strengths series two-mode systems conical intersection (CI), pyrazine molecule different solvent environments.