[gmx-users] K+ ion missing from gromos96ff in ions.itp file

[Mark Abraham]

----- Original Message -----
From: Dean Cuebas <deancuebas at missouristate.edu>
Date: Sunday, March 8, 2009 7:46
Subject: [gmx-users] K+ ion missing from gromos96ff in ions.itp file
To: "gmx-users at gromacs.org" <gmx-users at gromacs.org>

<font style="font-style: normal; font-weight: normal; background-color: rgb(245, 248, 240); font-size: 14px;">> </font>K+ ion missing from gromos96ff in ions.itp file



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> Dear gmxusers,

> 
> I am investigating intracellular proteins and NA+ ain’t the answer.

If you say so...

> Why is there no definition for K+ for GROMOS96 ff in the ions.itp file???
> I’m using gromacs3.3.1

... either because it was never parametrized, or never included in the version prepared for use with GROMACS.

>Yet it’s in the GROMACS ff and OPLS sections of the ions.itp file.

... because it was parametrized and was of sufficient interest for someone to included it in the version prepared for use with GROMACS.

> Is there a solution to this if I am using GROMOS96 force fields?

Read the primary literature for these force fields and see what ions were parameterized for use with it originally or subsequently.

Mark