On Sat, Nov 12, 2011 at 1:22 PM, Ismail, Mohd F. <farid.ou.edu> wrote:
> I am trying to simulate ions in bulk organic solvent. I use gaff for internal parameters. For charges, if I use bcc at first, but the density would not converge. When I use RED, the density is still about 3% higher.
>
> Will it be alright if I use higher method or basis set to calculate the charges? I saw some documentation that gaff and amber use HF with 6-31g* for the parameters and charges.
>
> I also check the trajectory, but there seems to be no 'stupid' conformation.
The charges are always very sensitive to the ab initio method applied.
Try MP2 instead, for example. BTW, 3% higher density is not so much
terrible for most tasks.
Dr. Vitaly V. Chaban, 430 Hutchison Hall, Chem. Dept.
Univ. Rochester, Rochester, New York 14627-0216
THE UNITED STATES OF AMERICA
_______________________________________________
AMBER mailing list
AMBER.ambermd.org
http://lists.ambermd.org/mailman/listinfo/amber
Received on Sun Nov 13 2011 - 13:00:04 PST
