[gmx-users] Gibbs Energy Calculation and charges

[Dallas Warren]

We have a molecule, and have run two sets of  Gibbs energy calculation, making the charge disappear. One molecule has the normal charges, the other all the charges are doubled. Taking the dHdl results for both and plotting against the charge of a selected atom (charge based at each lambda value) should those results over lap?

I thought that they would, since charge only is being changed, and it is a linear function of lambda. However, are getting some deviation closer to the lambda=0 values for the normal charge, it is lower than the double charged molecule around lambda = 0.5

Can provide graphs etc when I am back at my workstation. 

Any suggestions on whether should be over lapping or what we may be doing incorrectly?

Catch ya,

Dallas Warren