[gmx-users] Gibbs free energy

[mohammad agha]

Dear Steven,

Many thanks from your help. In the manual at the 
section g_energy has been written that the gromacs calculate the delta G
 as is follows:
"Delta G = G(N,p,T) - G idgas(N,p,T) = kT ln < eˆ(Upot/kT) >"
But
 I don't understand why Upot? to calculate of delta S, I know that 
"delta S = (internal energy + P*delta V- delta G)/T" but here has been 
written: Delta S(N,p,T) = S(N,p,T) - S idgas(N,p,T) = (<Upot> + pV
 - Delta G)/T.

May I ask you to answer me about this and the equation of delta G, Please? 


Best Regards
Sara