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Masoud Nahali
masoudnahali@gmail.com

Thanks for your reply. The proposed steps seems reasonable except the last part which is the main issue.
To construct the whole we must start from a point which in the case was the experimental result. Otherwise it is impossible to do global optimization. I think that I should apply some constraints to overcome the issue like forcing some chemical and van der waals bonds and angles to change only in a specific range defined by us. May be in such way we would encounter less difficulty to get convergence and find a local minimum with lower price. Is such capability available in FF or we may change the Fortran code to do that. Thanks again for your comment. Best Wishes, m


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Masoud Nahali
SUT
masoud.nahali@gmail.com
alum.sharif.edu/~m_nahali    




On Sun Oct 28 '12 11:46pm, sanya wrote
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>Dear Masoud,

>I'd recommend you to localize the problem. First, try to converge single-point SCF for the parts of your system: each ketone with its respective counter-ion and the rhenium-containing part. Each fragment is supposed to be neutral and closed-shell. You may also optimize the geometry of each fragment and construct the whole system from the optimized fragments.