[gmx-users] why DGbind=0 ?

[Albert]

Hello:

  I am using glie to evaluate my ligand binding affinity with command:

g_lie_d -f md.edr -o lie.xvg -ligand LIG

but I obtained the following results:

Opened md.edr as single precision energy file
Using the following energy terms:
LJ:
Coul:
DGbind = 0.000 (0.000)

@    title "LIE free energy estimate"
@    xaxis  label "Time (ps)"
@    yaxis  label "DGbind (kJ/mol)"
@TYPE xy
          0           0
       1000           0
       2000           0
       3000           0
       4000           0
       5000           0
       6000           0
       7000           0
       8000           0
       9000           0
      10000           0
      11000           0
      12000           0
      13000           0
      14000           0
      15000           0
      16000           0
      17000           0
      18000           0
      19000           0
      20000           0
      21000           0
      22000           0
      23000           0
      24000           0


I am just wondering why the result is zero?

thank you very much

Albert