Response function analysis of excited-state kinetic energy functional constructed by splitting k-space

Over the past decade, fundamentals of time-independent density functional theory for excited state have been established. However, construction of energy functionals for excited states remains a challenging problem. We have developed a method for obtaining these functionals by splitting k-space according to the occupation of orbitals. In this paper we demonstrate the accuracy of kinetic energy functional thus obtained for excited states with two sets of vacant orbitals. We then perform a response function analysis of the functional proposed and show why our method could be the method of choice for the construction of excited state energy functionals.