.. _ref-tools-equilibration:

Equilibration
-------------

Overview
^^^^^^^^

For a composite with fixed phases at a given pressure, temperature
and composition, equilibrium is reached when the following relationships are
satisfied:

.. math::
      0_i = R_{ij} \mu_j

where :math:`\mu_j` are the chemical potentials of all of the endmembers in
all of the phases, and :math:`R_{ij}` is an independent set of balanced
reactions between endmembers.

It is generally true that at a fixed composition, one can choose two
equilibrium constraints (such as fixed temperature, pressure, entropy, volume,
phase proportion or some composition constraint) and solve for the remaining
unknowns. In BurnMan, this can be achieved using the :func:`burnman.equilibrate`
function.

Implemented function
^^^^^^^^^^^^^^^^^^^^

.. autofunction:: burnman.equilibrate
    :no-index: