[gmx-users] water flow

[Justin Lemkul]

On 6/12/18 1:37 PM, Alex wrote:
> Hi Justin,
>
> Looking at acc-grps text in the manual, it's a bit unclear how a 
> constant flow rate would be achieved in this case. Is a constant force 
> in the amount of molecule mass, times the acceleration vector applied 
> to each molecule in the group, or is there actual acceleration 
> magically maintained?
>

I'm not familiar with the code, but it's what I know people have used to 
impose a constant force on a bulk solvent without having to use the pull 
code (which will throw errors).

-Justin

> Thanks,
>
> Alex
>
>
> On 6/12/2018 8:24 AM, Justin Lemkul wrote:
>>
>>
>> On 6/11/18 7:38 PM, Alex wrote:
>>> Hi all,
>>>
>>> I'm trying to explore pressure-induced processes, i.e. externally 
>>> induced
>>> water flow across a porous membrane that spans the entire box in XY. 
>>> There
>>> are obvious choices:
>>>
>>> 1. Introduce the same type of a membrane without pores and make it a 
>>> piston
>>> with pull code, e.g. constant force or tiny constant velocity along Z.
>>> 2. Apply constant force pull directly to the entire solvent group.
>>>
>>> Any other ideas on osmosis-like processes? Has anyone tried any of the
>>> options above?
>>
>> I would think the pull code would be more headache than it's worth in 
>> this case. I'd simply try inducing the flow with acc-grps.
>>
>> -Justin
>>
>

-- 
==================================================

Justin A. Lemkul, Ph.D.
Assistant Professor
Virginia Tech Department of Biochemistry

303 Engel Hall
340 West Campus Dr.
Blacksburg, VA 24061

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

==================================================