[gmx-users] Calculation of young's modulus from stress-strain plot

[Pragati Sharma]

Hello users,

I am trying to plot stress-strain curve for natural rubber from NPT
simulations using the "deform" option. Deform along x direction at 1 bar
pressure. The parameters I gave in mdp file are:

Pcoupl                   = Berendsen
Pcoupltype             = semiisotropic
tau_p                     = 2
compressibility        = 0 4.5e-5 4.5e-5
ref_p                       = 1   1    1
deform                   = 0.01 0 0 0 0 0

Q. Should I give six values to ref_P and compressibility also.
Q. If I give 'anisotropic'  coupling, then the error is
"ERROR 1: Pressure coupling incorrect number of values (I need exactly 6)"
Should I give the next three values as zero or 1. OR I can just use
semiisotropic coupling only.

Thanks in advance!!