[gmx-users] dielectric constant of water by gromacs

[David van der Spoel]

On 2014-05-30 07:39, Harshkumar Singh wrote:
> Can you please describe how to use pme or any other reference?
coulombtype = PME
in your mdp file.

>
>
> On Thu, May 29, 2014 at 3:40 AM, David van der Spoel <spoel at xray.bmc.uu.se>
> wrote:
>
>> On 2014-05-29 06:07, 来者可追 wrote:
>>
>>> Dear David,
>>>     I have a problem when simulating the dielectric constant of water
>>> according to g_dipoles.I used the water file in "tutor"(216 SPC waters),
>>> when I write the program "g_dipoles", the result is as following, why
>>> not Epsilon about 65?
>>>
>>> ‍=================================
>>> Finite system Kirkwood g factor G_k = 0.163272
>>> Infinite system Kirkwood g factor g_k = 0.123058
>>>
>>> Epsilon = 3.83011
>>> ‍‍=================================
>>>
>>>
>> Did you use PME? In that case it should work.
>> If you used a cut-off you have to redo the simulation.
>>
>>
>>
>>>     I cannot understand " you have to give extr options, depending on how
>>> you did the simulation. g_dipoles -h (hint look at the epsilonRF
>>> option). If you used a cut-off then you will not get the right
>>> dielectric. " (
>>> https://www.mail-archive.com/gmx-users%40gromacs.org/msg18306.html ) Can
>>> you explain it more for me? Thank you so much!
>>> ‍‍‍‍‍‍‍
>>>
>>> Sincerely,
>>> LiBin
>>>
>>>
>>>
>>
>> --
>> David van der Spoel, Ph.D., Professor of Biology
>> Dept. of Cell & Molec. Biol., Uppsala University.
>> Box 596, 75124 Uppsala, Sweden. Phone:  +46184714205.
>> spoel at xray.bmc.uu.se    http://folding.bmc.uu.se
>> --
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>
>
>


-- 
David van der Spoel, Ph.D., Professor of Biology
Dept. of Cell & Molec. Biol., Uppsala University.
Box 596, 75124 Uppsala, Sweden. Phone:	+46184714205.
spoel at xray.bmc.uu.se    http://folding.bmc.uu.se