I am interested to control temperature and pressure for a specific region using the NPT ensemble assigned to the yellow atoms (Heat region) in the image attached and NVE everywhere else composed of red atoms (NVE region). So, I want to use the following commands where x and z are periodic directions, and I want to achieve zero pressure for x, z, xz, and yz components while keep the temperature of the Heat region at 100K:
compute CtrlTemp Heat temp
fix 1 Heat npt temp 100 100 (100.0*dt) x 0.0 0.0 (1000.0dt) z 0.0 0.0 (1000.0*dt) xz 0.0 0.0 (1000.0dt) yz 0.0 0.0 $(1000.0*dt) tchain 10 tloop 10 pchain 10 ploop 10 nreset 1000
fix_modify 1 temp CtrlTemp press ???
fix 2 NVE nve
I appreciate it if someone can give me a hint on how to tune NPT command for the specific region Heat using fix_modify. By the way, are the commands above appropriate to control the temperature in the Heat region at 100K?
Many thanks in advance for your time and consideration,