# Gibbs energy of repulsion

In thermodynamics, Gibbs energy of repulsion, Gr is the measurement of the energy (or free energy?) associated with a repulsive force that exists or operates between two molecular objects, surfaces, or structures. In formulaic terms, Gibbs energy of repulsion is defined as follows: [1]

$G_r = \int_{l_i}^{l_f} F_r dl \bigg|_{T,P} \,$

where li is an initial length or distance of separation, lf is a final length or distance of separation, Fr is the repulsive force, dl is differential of length, and the where the conditional subscripts T and P signify an isothermal-isobaric process.

References
1. (a) Thims, Libb. (2007). Human Chemistry (Volume One). Morrisville, NC: LuLu.
(b) Attraction and Repulsion (Wayback)– IUPAC Reports, 2001.