[gmx-users] decimal charge instead of integer

[Erik Marklund]

Carla Jamous skrev:
> Hi,
>
> In order to run my simulation, I had to insert GDP parameters in 
> ffamber94 (the force field I'm using).
> However, I'm having a problem with GDP charge.
> the charge of every charge group in top file should be an integer. But 
> I'm getting a decimal charge which gives me naturally a decimal total 
> charge of my molecule.
> I checked number of atoms, it's correct, their charge also.
> But it seems it's having trouble adding charges & giving an integer 
> charge.
> Does anyone have an idea where is the source of the problem?
>
> Thanks
>
> Carla
I don't think amber uses charge groups, so there is no need to put that 
constraint on your set of charges. The moleculs as a whole must have 
integer charge though.

-- 
-----------------------------------------------
Erik Marklund, PhD student
Laboratory of Molecular Biophysics,
Dept. of Cell and Molecular Biology, Uppsala University.
Husargatan 3, Box 596,    75124 Uppsala, Sweden
phone:    +46 18 471 4537        fax: +46 18 511 755
erikm at xray.bmc.uu.se    http://xray.bmc.uu.se/molbiophys