67 research outputs found
Plane wave/pseudopotential implementation of excited state gradients in density functional linear response theory: a new route via implicit differentiation
This work presents the formalism and implementation of excited state nuclear
forces within density functional linear response theory (TDDFT) using a plane
wave basis set. An implicit differentiation technique is developed for
computing nonadiabatic coupling between Kohn-Sham molecular orbital
wavefunctions as well as gradients of orbital energies which are then used to
calculate excited state nuclear forces. The algorithm has been implemented in a
plane wave/pseudopotential code taking into account only a reduced active
subspace of molecular orbitals. It is demonstrated for the H and N
molecules that the analytical gradients rapidly converge to the exact forces
when the active subspace of molecular orbitals approaches completeness
Excited state tautomerism of the DNA base guanine: a restricted open-shell Kohn-Sham study
The relative stabilities of the six lowest energy tautomers of the DNA base guanine have been investigated in the first excite
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