[gmx-users] non-neutral system

[Hermann, Johannes]

Hey Joao,

are you sure? I think PME will introduce a neutralizing background charge?

All the best

Johannes


On 06.11.2017 11:57, João Henriques wrote:
> ​Hi,
>
> You shouldn't use PME without neutralizing the system's charge. ​It's a
> limitation of the Ewald summation. Take a look at the literature for
> further details.
>
> I don't know much about viscosity, so I'll leave that for someone else.
>
> Cheers,
> J
>
> On Mon, Nov 6, 2017 at 11:50 AM, Faezeh Pousaneh <fpoosaneh at gmail.com>
> wrote:
>
>> Hi,
>>
>> I  have a system containing similar charged atoms. So the total charge is
>> not zero.
>>
>> Simulation results with cut-off coulomb seems reasonable,  but using PME
>> they are wrong (total columb potential is negative value which must be
>> positive). Any idea why?
>>
>> If I use counter-ions to neutralize the system, I am afraid the properties
>> I am looking for (viscosity) will be influenced.
>>
>> Best regards
>> --
>> Gromacs Users mailing list
>>
>> * Please search the archive at http://www.gromacs.org/
>> Support/Mailing_Lists/GMX-Users_List before posting!
>>
>> * Can't post? Read http://www.gromacs.org/Support/Mailing_Lists
>>
>> * For (un)subscribe requests visit
>> https://maillist.sys.kth.se/mailman/listinfo/gromacs.org_gmx-users or
>> send a mail to gmx-users-request at gromacs.org.
>>

-- 
______________________________________
*Technische Universität München*
*Johannes Hermann, M.Sc.*
Lehrstuhl für Bioverfahrenstechnik
Boltzmannstr. 15
D-85748 Garching
Tel: +49 8928915730
Fax: +49 8928915714

Email: j.hermann at lrz.tum.de
http://www.biovt.mw.tum.de/