Re: Applying unidirectional pressure on a membrane protein system

From: Geist, Norman (
Date: Sat May 28 2022 - 02:19:50 CDT

I have answered this before. In a periodic cell there is no such
direction. Have you considered flipping the sign of

Norman Geist

Am Samstag, den 28-05-2022 um 08:38 schrieb Sruthi Sundaresan:

Dear Users,

I would like to know how to apply pressure on a membrane protein in
one direction. I am running the simulations on NAMD3.0 and used the
following lines in the input files to apply pressure:

useConstantArea         yes;

useflexiblecell         yes;
SurfaceTensionTarget    0.0;

langevinPiston          on;

langevinPistonTarget    4000.00;

langevinPistonPeriod    100.0;

langevinPistonDecay     50.0;

The above lines help to apply pressure on the z-axis alone while
keeping the area of the x-y plane constant. 
My system seems to get compressed along the z-axis, however, I'd like
to know how to apply pressure selectively in one direction alone
(either +z or -z).

Thanks and regards,


Sruthi Sundaresan

Ph.D. Research Scholar

C/o Dr. Thenmalarchelvi Rathinavelan

Molecular Biophysics Lab, Department of Biotechnology

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