[gmx-users] Surface tension calculations via gmx energy?

[Own 12121325]

Dear GROMACS users,

Using gmx energy I am trying to compute surface tension for the membrane
system in GROMACS under different surface tension. In the model surface
tension was modeled by various negative lateral pressure:

Pxy surf*surftension

1 bar -33.8847
-10 bar 155.696
-20 bar 240.326
-30 bar 277.994
-40 bar 367.037

Now I need to extract from these values a value for surface tension in
dyn/cm (1 bar*nm = 0.1 mN/m = 0.1 dyn/cm).

Question: what is the number of surfaces [surf*] should be for membrane
system?

Thanks in advance