[gmx-users] charmm36M generated topology conversion to GROMOS54A7 ff

[Justin Lemkul]

On 10/2/19 2:03 PM, Yogesh Sharma wrote:
> hi users,
> I generated ligand topology containing complex metals using ATB server,
> developed using GROMOS54A7 modified  forcefield. Then i used Charmm gui for
> protein embedding in lipid bilayer followed by catenation of both .gro
> files.  System was solvated but during ion addition it couldnot recognize
> ligand metal atoms probably because of unmodified charmm 36m which doesnt
> have parameters for metals. I want to use ATB generated modified gromos54A7
> instead. How can I generate gromac topology for the combined system so that
> i could use that with  modified forcefield?

You can't mix and match force fields. Everything needs to be developed 
under one, consistently developed, force field. You also can't convert 
parameters between different force fields.

-Justin

-- 
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Justin A. Lemkul, Ph.D.
Assistant Professor
Office: 301 Fralin Hall
Lab: 303 Engel Hall

Virginia Tech Department of Biochemistry
340 West Campus Dr.
Blacksburg, VA 24061

jalemkul at vt.edu | (540) 231-3129
http://www.thelemkullab.com

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