CCL: CL: koopmans' theorem



Hello:

In my opinion, Koopmans' theorem is based on frozen orbital approximation, therefore it is uneccessary to relax the nuclei configuration. If you intend to get a adiabatic ionization, however, delta SCF is more sutible.


Cheers!

Jun Zhang
Nankai University
coolrainbow,+,yahoo.cn


 Shirin Seifert shirin.seifert|-|gmail.com <owner-chemistry,+,ccl.net>
 CCL: koopmans' theorem
 "Zhang, Jun -id#3zy-" <coolrainbow,+,yahoo.cn>


Hi,

On using the koopmans' theorem to estimate the first and second ionization energy of a cation, should the geometry of the molecule be that of the cation (but neutral)? or the considered geometry is from the optimized neutral molecule?

Thanks for your explanation in advance.

Regards,
S.S