[gmx-users] lambda dependence for free energy calc

[Ilya Chorny]

Hi 

Why is the Lambda dependence on the on the potential non linear? (.i.e.
(1-Lambda).5 ka(r-(1-Lambda)ra)^2+  Lambda*.5 kb(r-Lambda*rb)^2 vs.
(1-Lambda).5 ka(r-ra)^2+  Lambda*.5 kb(r-rb)^2). The latter possibility
would allow me to do use a statistical perturbation approach when
calculating free energy but the former only allows for slow growth( is
that correct?)

Also is there a way to turn off the C6 contribution to the Lennard Jones
Potential?

Thanks

Ilya

P.S.

Gromacs Rocks!!!!