Workaround for divide-by-zero error in double differentiation of higher-order interaction parameters. A cancellation check in the generalized power rule code will eventually need to be added.
Workaround for divide-by-zero error in double differentiation of higher-order interaction parameters. A cancellation check in the generalized power rule code will eventually need to be added.

tkphd/pycalphad,tkphd/pycalphad,tkphd/pycalphad