[gmx-users] time constants for the Parrinello-Rahman/nose-hoover coupling

[Hwankyu Lee]

Dear GMX-users,

I'm simulating lipid bilayer, and since fluctuation is important for 
the study of undulation and area compressibility (Ka), I'm also 
applying the Parrinello-Rahman and nose-hoover for the pressure and 
temperature couplings. When I use the Berendsen, time constants are 
like below.  When I use the PR, do I need to change time constants?  
Thank you for your time and help in advance.

----------------
tcoupl                   = Berendsen
; Groups to couple separately = tc-grps                  = DPP W ; Time 
constant (ps) and reference temperature (K) = tau_t                    
= 0.5 0.5
ref_t                    = 323  323
; Pressure coupling      = Pcoupl                   = Berendsen 
Pcoupltype               = Semiisotropic
; Time constant (ps), compressibility (1/bar) and reference P (bar) = 
tau_p                    = 1.2   1.2 compressibility          = 5e-5  
5e-5   ref_p                    = 1.0 1.0 ------------------

best,
Hwankyu.