[gmx-users] Question regarding the concept of ensembles

[ali.khourshaei71 at student.sharif.edu]

Dear Gromacs users, 

I have 4 question regarding the concept of the ensemble. 

1.  In NVT ensemble the length of the simulation box remains constant in
x,y and z direction. Does it mean that all the atoms within the system
become freeze and have no movement? 

2. In NPT ensemble if I choose compressibility = 0 in one specific
direction, does the length of the simulation box only becomes constant
in that direction or all the atoms become freeze in that direction too? 

3. Is NVT ensemble equivalent to NPT ensemble with negligible
compressibility in x,y, and z direction? 

4. To constant the thickness of the simulation box, is there any
difference if I choose compressibility = 0 or choose tau-p as very high
amount?