[gmx-users] PMF and jacobian correction

[Sanku M]

Dear Gromacs user,
  I was having a question on when need to use jacobian coorection of -2KTln(r) ( gromacs manual chapter 6) term when calculating PMF. I understand for a 3-dimensional radial coordinate like distance between two groups, this term need to taken care of. But, if the PMF is computed along Radius of gyration which is an internal coordinate, I was wondering whether this jacobian correction still needs to be subtracted.
Any help in sorting out this confusion will be appreciated.
Sanku