2 papers
physics.chem-ph2026
Analytic first-order non-adiabatic coupling matrix elements of spin-adapted open-shell time-dependent density functional theory
Xiaoli Wang, Xingwen Wang, Zikuan Wang +1
While spin-adapted time-dependent density functional theory (TDDFT) approaches significantly improve the excitation energies and gradients of open-shell molecules, the effect of sp…
physics.chem-ph2025
O1NumHess: a fast and accurate seminumerical Hessian algorithm using only O(1) gradients
Bo Wang, Shaohang Luo, Zikuan Wang +1
In this work, we describe a new algorithm, O1NumHess, to calculate the Hessian of a molecular system by finite differentiation of gradients calculated at displaced geometries. Diff…