Hi lammps-users
I do not fully understand which compute style fix style uses when thermostating is applied when I read the manual. I just want to the temperature is adjusted according to the temperature of the group.
If I use following command
compute flow_tem thermol_group temp
fix lng thermol_group langevin 300 300 100 123456
Although I have define the computation of the group and also use the same group for fix style, Lammps still uses the default compute style which is “compute thermo_temp all temp” to adjust the temperature. Is it right? To overwrite the default compute style and use the user-defined style, I have to use the fix_modify command, like following commands
compute flow_tem thermol_group temp
fix lng thermol_group langevin 300 300 100 123456
fix_modify 1 temp flow_tem
Is my understanding right?
And this is also the case for the barostatting when the pressure is adjusted, is it right?
Fan Li
Hi lammps-users
I do not fully understand which compute style fix style uses when
thermostating is applied when I read the manual. I just want to the
temperature is adjusted according to the temperature of the group.
If I use following command
compute flow_tem thermol_group temp
fix lng thermol_group langevin 300 300 100 123456
Although I have define the computation of the group and also use the same
group for fix style, Lammps still uses the default compute style which is
"compute thermo_temp all temp" to adjust the temperature. Is it right?
no, that is wrong. thermo_temp is for thermodynamic output. it is never
used for thermostats. thermostats will create their own compute with the id
being derived from the fix id and the group being the same group as the fix
group.
To overwrite the default compute style and use the user-defined style, I
have to use the fix_modify command, like following commands
compute flow_tem thermol_group temp
fix lng thermol_group langevin 300 300 100 123456
fix_modify 1 temp flow_tem
Is my understanding right?
not really. this will work, but it will result in exactly the same
behavior as the default without fix_modify.
BTW: you can check which computes are defined using the "info" command.
And this is also the case for the barostatting when the pressure is
adjusted, is it right?
barostatting is not so straightforward. while you can compute and adjust
the kinetic energy of individual atoms, pressure is a global property and
you can only adjust the volume for the whole system.
axel.