Dear Ge Song,
For compute temp:
(from: http://lammps.sandia.gov/doc/compute_temp.html)
This compute subtracts out degrees-of-freedom due to fixes that constrain molecular motion, such as fix shake and fix rigid. This means the temperature of groups of atoms that include these constraints will be computed correctly. If needed, the subtracted degrees-of-freedom can be altered using the extra option of the compute_modify command.
For compute temp/region:
http://lammps.sandia.gov/doc/compute_temp_region.html
Unlike other compute styles that calculate temperature, this compute does NOT currently subtract out degrees-of-freedom due to fixes that constrain molecular motion, such as fix shake and fix rigid. If needed the subtracted degrees-of-freedom can be altered using the extra option of the compute_modify command.
Best,
Mario
Message: 7