[gmx-users] -rerun with energygrps

[Alex]

Hi all,

Something funny is happening. I have a very simple system: an ion in bulk
TIP4P water running under OPLS-AA. mdp excerpt below:

nstlist             =  20
pbc                 = xyz
periodic_molecules  = yes
ns_type             =  grid
rlist               =  1.0
coulombtype         =  pme
fourierspacing      =  0.135
rcoulomb            =  1.0
rvdw                =  1.0
vdwtype             =  cut-off
cutoff-scheme   = Verlet

In order to determine ion-solvent interaction energy, i have a rerun mdp
that is identical to the one used for the actual simulation, but with

energygrps = K SOL

added. When applying gmx energy to the rerun edr, the only K-SOL options
are:

41  Coul-SR:K-SOL
42  LJ-SR:K-SOL

Nothing long-range. This has never been the case before and PME
contribution was always there.

Any suggestions?

Thank you,

Alex