Analytical energy gradients of Coulomb-attenuated time-dependent density functional methods for excited states

摘要

We present an implementation and validation of the analytical energy gradient of time-dependent density functional theory (TDDFT) using Coulombattenuated (CA) functionals for excited state energies, dipole moments, geometries, and vibrational frequencies. The CA-TDDFT gradient is based on the previous long-range corrected TDDFT of (Chiba et al. J Chem Phys 2006, 124, 144106) and the Z-vector formalism of (Furche and Ahlrichs J Chem Phys 2002, 117, 7433). Geometry optimization using CA-TDDFT was carried out for molecules (substituted stilbenes and coumarins) having intramolecular charge-transfer excited states and for a series of small molecules (CO, HCN, CH_2O, CH_2S, CCl_2, C_2H_2, trans-(CHO) _2). We assess the results of the CA functionals, the long-range corrected LC-BLYP functional, and the B3LYP hybrid functional, by comparing to accurate experimental data. The results highlight the applicabilty of different functionals for excited state properties.