[gmx-users] problem using g_lie

[khushboo bafna]

hii

I ran a protein ligand simulation and only ligand simualtion in water using
GROMACS 4.5.4
I want to find the binding energy of the ligand and used g_lie.

I tried to run g_lie on ligand simulation in water and got the following
result

Opened md_1.edr as single precision energy file
Using the following energy terms:
LJ:
Coul:

Back Off! I just backed up lie.xvg to ./#lie.xvg.3#
Last energy frame read 2500 time 5000.000
DGbind = -0.681 (-nan)

Can anyone tell me what is the problem and how to go about with this