Finite-basis-set implementation of subspace density-functional theory for excited states - art. no. 064501

The aim of this paper is to study the peculiarities arising in a finite-bas is-set implementation of the subspace density-functional theory (SDFT) for the excited states of molecules. The accuracy of different basis-set calcul ations is discussed within the framework of the local-density approximation , Small basis sets with adjustable parameters, optimized for each subspace energy, were found to provide a balanced description of states. On the cont rary. basis sets adjusted to the ground state yield a poor approximation fo r the excited states. For the molecules under consideration (H-2, HeH, and LiH), the SDFT accuracy for excited states compares well with ground-state density-functional theory calculations. Despite the limited basis set used the excitation energies calculated are in agreement with the more accurate ones obtained within the wave-function formalism by the configuration inter action methods.