CCL: intramolecular proton transfer

["yang zhen na" <yangzn553-$-nenu.edu.cn>]

 Sent to CCL by: "yang zhen na" [yangzn553[]nenu.edu.cn]
 I calculate the proton transfer reaction of a molecule, the experiment revealed
 that in the ground state the enol form is more stable than the keto form, but in
 the excited state keto form is more stable than the enol form.
 First, the energy of the excited state was obtained by summing the energy of the
 ground state and the corresponding excitation energy. And get the conclusion
 that keto form is more stable the enol form in the first excited state.
 Sencod, I optimize the geometries of two forms in the excited state using cis
 method and find the energy by keywords scf done. But the conclusion is that enol
 form is more stable than the keto form.
 I dont know why different methods get different conclusion and which one is
 right. The first method is agreement with the experiment value. So I think
 whether there is two mechanisms for proton transfer in the excited state. First,
 the proton transfers as the molecule get the excited state and the geometry have
 not been changed. Second, the molecule relaxes first and then the proton
 transfers, the molecule I studied is obey the first mechanism. I dont know
 whether I am right, please help me and give me an answer.
 I am anxious of getting your help. Think you with the great wishes!