Free-energy calculations - Theoretical Biophysics Group

Free-energy perturbation calculations Introduction
Perturbation theory is one of the oldest and most useful, general techniques in applied
mathematics.
Its initial applications to physics were in celestial mechanics, and its goal was to
explain how the presence of bodies other than the sun perturbed the elliptical orbits
of planets.
Although applications of perturbation theory vary widely, the main idea remains the
same: One starts with an initial problem, called the unperturbed or reference problem.
The problem of interest, called the target problem, is represented in terms of a perturbation
to the reference problem.
The effect of the perturbation is expressed as an expansion in a series with respect
to a small quantity, called the perturbation parameter.
Chris Chipot Free-energy calculations