Request for Heckmann diagram/tensor property relations to be implemented

[mkhorton]

e.g. applied_stress + elastic_tensor + lattice --> strained lattice etc.

see also https://static.cambridge.org/content/id/urn%3Acambridge.org%3Aid%3Aarticle%3AS215968591600029X/resource/name/S215968591600029X_figAb.jpeg?pub-status=live

Thinking specifically for tensor properties, could probably use a common tensor implementation (eg from pymatgen.core.tensor). There are some edges of the diagram that don't make sense/aren't practicable to implement right now.

[mkhorton]

Basically the equations here: https://en.wikipedia.org/wiki/Constitutive_equation (specifically mechanical, thermoelectric and electromagnetic properties). These are basic enough that I think they should be required prior to any v1 of propnet.