get_elastic_tensor_from_coeffs

torch_sim.elastic.get_elastic_tensor_from_coeffs(Cij, bravais_type)[source]

Convert the symmetry-reduced elastic constants to full 6x6 elastic tensor.

Parameters:
  • Cij (Tensor) – Tensor containing independent elastic constants for the given symmetry

  • bravais_type (BravaisType) – Crystal system determining the symmetry rules

Returns:

Full 6x6 elastic tensor with all components

Return type:

Tensor

Notes

The mapping follows Voigt notation where: 1 = xx, 2 = yy, 3 = zz, 4 = yz, 5 = xz, 6 = xy

The number of independent constants varies by symmetry: - Cubic: 3 (C11, C12, C44) - Hexagonal: 5 (C11, C12, C13, C33, C44) - Trigonal: 6 (C11, C12, C13, C14, C33, C44) - Tetragonal: 7 (C11, C12, C13, C16, C33, C44, C66) - Orthorhombic: 9 (C11, C22, C33, C12, C13, C23, C44, C55, C66) - Monoclinic: 13 constants (C11, C22, C33, C12, C13, C23, C44, C55,

C66, C15, C25, C35, C46)

  • Triclinic: 21 constants