quantity.observables.stiffness_tensor_components_cubic_crystal

quantity.observables.stiffness_tensor_components_cubic_crystal#

stiffness_tensor_components_cubic_crystal(stiffness_tensor)[source]#

Computes the 3 independent elastic stiffness components of a cubic crystal from the whole stiffness tensor.

The number of independent components in a general stiffness tensor is 21 for isotropic pressure. For a cubic crystal, these 21 parameters only take 3 distinct values: c11, c12 and c44. We compute these values from averages using all 21 components for variance reduction purposes.

Parameters:

stiffness_tensor – The full (3, 3, 3, 3) elastic stiffness tensor

Returns:

A (3,) ndarray containing (c11, c12, c44)