| Static thermodynamic susceptibilities obey symmetries that have been known for a very long time. These are the Maxwell relations. Less well-known are the symmetry properties that are consequences of a certain type of perturbation. These are the Le Chatelier reciprocal relations. These involve relaxation of thermodynamic extensive and intensive parameters to new static equilibrium values after a sudden perturbation. Since time-dependent thermodynamic properties are governed by the fundamental equations of nonequilibrium thermodynamics, we expect the time constants of these relaxations to be governed, to some extent, by Onsager's kinetic coefficients. In this work we address the time scales and symmetries of these relaxation processes which have not been previously addressed. We explore the relation between the static susceptibilities (Maxwell relations) of equilibrium thermodynamics, the symmetries of the Le Chatelier reciprocal relations, as contained in the Le Chatelier matrix, the symmetries of the kinetic coefficients, which govern the relaxation dynamics of nonequilibrium processes, and the symmetries of the Fluctuation-Dissipation theorem. |
