  An LDA exchange potential is proposed for excited states and to test this
potential we apply it to the excited states of atomic system. The potential is
an approximate functional derivative of an accurate exchange energy functional
for excited states. We show that the potential satisfies Levey- Perdew theorem
for exchange energy and janak theorem for orbital energy very well in excited
state cases. The potential is the first of its kind for excited state and can
easily be generalized to other excited states of interest. We compare our
results with those of other approaches reported in the literature.
