Hi Gromacs user ,<br> <br> In justin tutorial protein-ligand complex..<br><br><a href="http://www.bevanlab.biochem.vt.edu/Pages/Personal/justin/gmx-tutorials/complex/08_MD.html">http://www.bevanlab.biochem.vt.edu/Pages/Personal/justin/gmx-tutorials/complex/08_MD.html</a><br>
<br>the production md.mdp has following parameter for Pressure and Temperature coupling <br><br><pre>; Temperature coupling is on
tcoupl = V-rescale ; modified Berendsen thermostat
tc-grps = Protein_JZ4 Water_and_ions ; two coupling groups - more accurate
tau_t = 0.1 0.1 ; time constant, in ps
ref_t = 300 300 ; reference temperature, one for each group, in K
; Pressure coupling is off
pcoupl = Parrinello-Rahman ; pressure coupling is on for NPT
pcoupltype = isotropic ; uniform scaling of box vectors
tau_p = 2.0 ; time constant, in ps
ref_p = 1.0 ; reference pressure, in bar
compressibility = 4.5e-5 ; isothermal compressibility of water, bar^-1
; Periodic boundary conditions
pbc = xyz ; 3-D PBC</pre><br><br>My query is ..Why Pressure Coupling is off in production MD run ???<br><br>With Best Wishes,<br><br><br><br><br>