[gmx-users] User tabulated potentials with cutoff-scheme = verlet, GROMACS 5.0.1 and 5.0.2

[Francesco Mambretti]

Dear all, I am a student in Physics at Milan University. For my thesis, I
should run a simulation of a binary liquid mixture of Argon and Krypton. 

Until now, I have been learning how to use GROMACS (version 5.0.1 and, since
yesterady, 5.0.2) essentials, and my simulations were all based on LJ
potential, and all was fine.
 
Now I want to use a tabulated potential, that is a more detailed potential,
different in form from LJ, taken from literature.
I followed the steps of the instructions on GROMACS website
(http://www.gromacs.org/Documentation/How-tos/Tabulated_Potentials?highlight=tabulated+potential)
and the attached pdf, but it doesn't work. 
I ought to use cutoff-scheme = verlet (because the "group" scheme does not
make sense, because my system has no charge), but I receive these errors
from grompp:

ERROR 1 [file Aziz.mdp]:
  With Verlet lists only cut-off and PME LJ interactions are supported


ERROR 2 [file Aziz.mdp]:
  With Verlet lists only cut-off, reaction-field, PME and Ewald
  electrostatics are supported

Aziz.mdp is my mdp file, that contains the instructions coulombtype = User
and vdwtype = User.

What am I missing?
Or it is true that GROMACS is not able to use user-defined potentials with
verlet's cutoff? This would be a serious handicap for this code! 
Am I forced to use charge groups?

Thanks in advance,

Francesco Mambretti - University of Milan - LCP (Parallel Computing Lab)