Free-energy calculations - Theoretical Biophysics Group

Reaction coordinate–based free-energy calculations A vector field approach
From P(x; δξ) = x + δξ V(x), it follows to first order
in δξ, that the potential energy changes by:
δUi(ξ)
δξ
= V · ∇xU(x)
From the fact that vector x2 − x1 is projected onto
x2 − x1 + δξ(x2 − x1) · ∇xV(x1), it follows to first order
in δξ, that the kinetic term changes by:
1 δvi(ξ)
= ∇x · V
vi(ξ) δξ
Derivative of the free energy with respect to the order
parameter: 51
dA(ξ)
dξ =
V · ∇xU(x) − 1
∇x · V
β ξ
51 DEN OTTER (2000)
Chris Chipot Free-energy calculations