2024/10/29 by Davood B. Dar, Neepa T. Maitra, Dar, Davood B. +1 · 4 citations
Chemistry · Physics and Astronomy · #Advanced Physical and Chemical Molecular Interactions #Chemical Physics (physics.chem-ph) #FOS: Physical sciences #Mechanical and Optical Resonators #Photorefractive and Nonlinear Optics
paper · pdf · doi:10.48550/arxiv.2410.22286
openalex publication_date 2024/10/29 · openalex created_date 2024/11/14 · openalex updated_date 2026/07/28
A striking example of the need to accurately capture states of double-excitation character in molecules is seen in predicting photo-induced dynamics in small polyenes. Due to the coupling of electronic and nuclear motions,the dark 21Ag state, known to have double-excitation character, can be reached after an initial photo-excitation to the bright 1Bu state via crossings of their potential energy surfaces. However, the shapes of the surfaces are so poorly captured by most electronic structure methods, that the crossing is missed or substantially mis-located. We demonstrate that the frequency-dependent kernel of dressed TDDFT beyond Tamm-Dancoff successfully captures the curve-crossing, providing an energy surface close to the highly accurate but more expensive δ-CR-EOMCC(2,3) benchmark reference. This, along with its accurate prediction of the excitation character of the state makes dressed TDDFT a practical and accurate route to electronic structure quantities needed in modeling ultrafast dynamics in molecules.