CCL:optimization in the excited state (CIS, G03)



Dear colleages,
 Recently I encountered a problem with geometry optimization in S1 state by CIS
 method (realized in G03).
 First of all the total energy did not decrease from larger value to the smaller
 one, but increased (!), then the optimization process began to oscillate between
 two structures.
 Could you suggest the explanation (and possible remedy) for this behaviour?
 I'm sorry if I ask the question that was already answered.
 Thank you in advance,
 Igor Avilov.