[lammps-users] checking conservation of extended hamiltonian for rigid body nvt dynamics

Dear LAMMPS users and developers,
I would like to check that the extended nvt hamiltonian (H_nvt) for rigid bodies is approximately conserved - and have been peering into the source code of fix_rigid_nvt with the hope of finding it there (i.e. the code for eq 12 of Kamberaj et al, J. Chem. Phys , 122, 224114 (2005) ) but unless I am mistaken it is not explicitly given. Am I right - and if so should I modify the fix so as to print it out - or have the contributes of this fix to lammps have already done so (very likely I would imagine) ? I am of course eager to NOT reconstruct the wheel… What I have in mind is the equivalent expression for the rigid body case to what appears explicitly in the fix_nh.cpp for non-rigid bodies for the energy the thermostats. By the way, the fix_nh.cpp code is so full of explicit references that it is a pleasure to read - and the additional energies due to the thermostats/barostats are readily output as a LAMMPS scalar.

Thanks a 1000 for any help/hints.

Best Regards,


Dr Donal MacKernan
Advanced Molecular Simulation Research Laboratory
School of Physics, University College Dublin, Ireland