[gmx-users] implementation of charges from QM

[B. Nick]

Dear all,

I have to do MD with a small organic molecule
showing some unusual atom groups. To have "good" 
charges for the specific atoms I got values
from QM that I now want to implement into the
OPLS-AA force field. I wonder that the new, QM 
derived charges are about twice as large as the
charges of similar atom groups of the OPLS-AA 
force field. Is there a specific procedure to 
implement QM results to force fields, so that 
the new electrostatic fit with the rest of the 
parameter?

Thanks for any suggestions,
Gitta
 

-- 
Dr. Birgitta Nick
DWI an der RWTH Aachen,
Veltmanplatz 8,
52062 Aachen, Germany