[gmx-users] g_lie reproducibility (g_lie is lying)

Tom Dupree t.dupree at unsw.edu.au
Thu Jun 14 07:56:48 CEST 2012


Greetings all,
I can't manually reproduce g_lie results.
After raging at excel for a while I think I have found a bug.

Here is my first time point,
Reported by g_lie to be 35.0073
>From energy file
Lj_complex =-130.762
Coul_complex = -286.746
My constants specified to g_lie
Clj = Alpha = lj_const = 0.181 
Cqq = Beta = coul_const = 0.43
Elj = Lj_solv = -166
Eqq = Coul_solv = -263

Therefore
Lj_diff = 35.238
Coul_diff = -23.746

Hence 
Lj_diff x lj_const = 6.378
Coul_diff x coul_const = -10.211

And there is no way I can add those to get 35.0073

However I can get this value using the following
Coul_complex - lj_solv = -120.746
Lj_complex - coul_solv = 132.2378
-120.746 x lj_const = -120.746 x 0.181 = -21.855
132.2378 x coul_const = 56.86225
Sum = 35.00726

In short I think the g_lie calculation has swapped its variables, Elj instead of Eqq and vice versa.
 
One other thing I have noticed is that when calculating the average g_lie uses the final value twice, is there a reason for this?

e.g.

 994 24.9397
 996 43.3382
 998 40.5714
1000 40.5585
1000 40.5585

All the best,
Tom




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