29.03.2013 Views

Free-energy calculations - Theoretical Biophysics Group

Free-energy calculations - Theoretical Biophysics Group

Free-energy calculations - Theoretical Biophysics Group

SHOW MORE
SHOW LESS

You also want an ePaper? Increase the reach of your titles

YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.

Reaction coordinate–based free-<strong>energy</strong> <strong>calculations</strong> A backdrop on potential of mean force <strong>calculations</strong><br />

ξ and {x} are not independent variables:<br />

<br />

Pξ =<br />

<br />

|J| exp[−βU(q; ξ)] dq exp[−βT(px)]dpx<br />

Derivative of the probability distribution with respect to ξ:<br />

dPξ<br />

dξ<br />

=<br />

×<br />

<br />

<br />

exp[−βU(q; ξ)]<br />

exp[−βT(px)] dpx<br />

The kinetic contribution vanishes in dA(ξ)/dξ:<br />

dA(ξ)<br />

dξ<br />

<br />

∂U(q; ξ)<br />

−β|J| +<br />

∂ξ<br />

∂|J|<br />

<br />

dq<br />

∂ξ<br />

= − 1<br />

<br />

1<br />

exp[−βU(q; ξ<br />

β Pξ<br />

∗ )] δ(ξ ∗ − ξ)<br />

<br />

× −β|J| ∂U(q; ξ∗ )<br />

+<br />

∂ξ<br />

∂|J|<br />

<br />

dq dξ<br />

∂ξ<br />

∗<br />

Chris Chipot <strong>Free</strong>-<strong>energy</strong> <strong>calculations</strong>

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!