Material parameters for each unique material are read from JSON files that are human-readable and editable.

The structure of the material file is as follows: { “Name”: “BiFeO3”, “Ferroelectric” : { “Is_FE” : true, “Tc” : 1100.0, “Mass” : 1.35e-18, “Damping” : 2.0e-7, “Landau” : { “Order” : 4, “a1” : -3.580e8, “a11” : 3.000e8, “a12” : 1.188e8 }, “Gradient” : { “G11” : 5.1e-10, “G12” : 0.0, “G44” : 0.0 } }, “Electrical” : { “RelativePermittivity” : [ [10.0, 0.0, 0.0], [0.0, 10.0, 0.0], [0.0, 0.0, 10.0] ], “ComplexPermittivity” : [ [0.0, 0.0, 0.0], [0.0, 0.0, 0.0], [0.0, 0.0, 0.0] ], “Conductivity” : 0.0 }, “Mechanical” : { “ElasticConstants” : { “C11” : 1.78e11, “C12” : 0.964e11, “C44” : 1.22e11 }, “Electrostrictive” : { “Q11” : 0.1, “Q12” : -0.034, “Q44” : 0.029 }, “Flexoelectric” : { “f11” : 0.0, “f12” : 0.0, “f44” : 0.0 } } } #