Hi all,
I simulated a collision system with two groups. One is the active region inner, the other “side” is the thermostat region outside the system.
And group s1 is one of the atoms in the active region. The thermostat region is to absorb the inner energy of the system during the collision.
The partial input script is as follows.
group side …
group s1 …
fix 3 side nve
compute ru side temp
fix 4 side temp/rescale 10 300 300 5.0 1.0
fix_modify 4 temp ru
velocity s1 set 0.0 1000 0.0
dump all cfg 100 cu16/cu.*.cfg id type xs ys zs
#thermo_modify temp
timestep 0.001
run 10000
The running result is the following when close the themo_modify command.
Step Temp E_pair E_mol TotEng Press Volume
110 52084.603 -542881.98 0 342524.48 555533.73 1829687.8
120 52091.315 -542996.13 0 342524.42 555068.5 1829687.8
130 52102.062 -543178.92 0 342524.32 554622.1 1829691.4
140 52112.125 -543350.05 0 342524.25 554333.76 1829691.4
150 52119.66 -543478.23 0 342524.17 554239.94 1829691.4
The running result is the following when open the themo_modify command.
Step Temp E_pair E_mol TotEng Press Volume
110 300 -542881.98 0 -542266.92 39018.649 1829687.8
120 300 -543004.85 0 -542389.79 38490.658 1829687.8
130 300 -543213.99 0 -542598.93 37884.08 1829687.8
140 300 -543423 0 -542807.94 37387.837 1829691.9
150 300 -543603.09 0 -542988.03 37041.153 1829691.9
My question:
- The system temperature was stable when open the themo_modify command.
The system temperature was so high, up to 52000 K, when close themo_modify command. Why?
Didn’t the thermostat play a role? - I can’t seemingly see the collision phenomenon. Where is the problem of the above settings?
Any suggestions are welcome.
Thanks.
Best regards,
Pan