VMD-L Mailing List

From: Vermaas, Joshua (Joshua.Vermaas_at_nrel.gov)
Date: Fri Jul 13 2018 - 20:43:10 CDT

Hi Ushasi,

What are the restraints you are putting on the charges? Normally, I find that I need to bound the optimization area to a region much smaller than the defaults to get reasonable answers. I think its a matter of the optimization getting lost in the wilderness due to the optimizer just going "downhill" in any which way with too large of a step. Usually, I do not include the hydrogens in the optimization, and aggressively group similar atoms together to bind them to have the same charge.

-Josh

On 2018-07-12 04:52:23-06:00 owner-vmd-l_at_ks.uiuc.edu wrote:

Hello all,
I am new in the parametrization field. I have tried with the tutorial in ffTK given in the screencast and pdf document. I got the results same as provided. But when I am trying to apply same method to some other known molecules already given in CGenF I am not getting the charges close to CGenF.
Can anyone help me regarding this as I am stuck into the problem from last 2 months.
Ushasi 

--
USHASI PRAMANIK
Ph.D. student
IISER Bhopal
Dept of Chemistry
Thesis Supervisor: Dr. Rajesh Kumar Murarka
Academic Building 2, Lab No. 202
Roll No. 1710228
Computational Biophysics and Soft Matter Group  <https://na01.safelinks.protection.outlook.com/?url=https:%2F%2Fhome.iiserb.ac.in%2F~rkm%2F&data=02%7C01%7CJoshua.Vermaas%40nrel.gov%7C37b293ef52ec462a1d2e08d5e7e58a54%7Ca0f29d7e28cd4f5484427885aee7c080%7C0%7C0%7C636669895426334209&sdata=Z6tOZ6om0o4IeEIwBQojRKXeZQRfgfMyJVHyqQb3FKs%3D&reserved=0>
https://home.iiserb.ac.in/~rkm/&sdata=Z6tOZ6om0o4IeEIwBQojRKXeZQRfgfMyJVHyqQb3FKs%3D&reserved=0>
email: ushasi17_at_iiserb.ac.in<mailto:ushasi17_at_iiserb.ac.in>