[gmx-users] Lambda Dependence when delta_lambda = 0

[Ilya Chorny]

So in the case of a Ar in H2O where the potential is just a LJ. the
derivative for all Lambda is just the Difference in the potential
between two states as is shown by Eqn 4.78 in the manual. I am getting
numbers that are about 7500 KJ/mol for dh/dl. Doesn't that seem a little
large? Should not the difference in energy be negative when state B has
a smaller sigma(less by one angstrom) then state A?

Ilya

here is an example of my output from dgdl.xvg. 

0 7576.69
0.001 7275.79
0.002 7309.38
0.003 7543.01
0.004 7615.15
0.005 7442.13
0.006 7332.6
0.007 7559.46
0.008 7961.26
0.009 8111.05