piezoelectric_tensor¶

The piezoelectric tensor is the derivative of the energy with respect to strain and field.

The piezoelectric tensor represents the coupling between mechanical stress and electrical polarization in a material. VASP computes the piezoelectric tensor with a linear response calculation. The piezoelectric tensor is a 3x3 matrix that relates the three components of stress to the three components of polarization. Specifically, it describes how the application of mechanical stress induces an electric polarization and, conversely, how an applied electric field results in a deformation.

The piezoelectric tensor helps to characterize the efficiency and anisotropy of the piezoelectric response. A large piezoelectric tensor is useful e.g. for sensors and actuators. Moreover, the tensor’s symmetry properties are coupled to the crystal structure and symmetry. Therefore a mismatch of the symmetry properties between calculations and experiment can reveal underlying flaws in the characterization of the crystal structure.

print()¶

Print a string representation of this instance.

read(*args, **kwargs)¶

Convenient wrapper around to_dict. Check that function for examples and optional arguments.

selections()¶

Returns possible alternatives for this particular quantity VASP can produce.

The returned dictionary contains a single item with the name of the quantity mapping to all possible selections. Each of these selection may be passed to other functions of this quantity to select which output of VASP is used.

Returns:

The key indicates this quantity and the values possible choices for arguments to other functions of this quantity.

Return type:

dict

to_dict()¶

Read the ionic and electronic contribution to the piezoelectric tensor into a dictionary.

It will combine both terms as the total piezoelectric tensor (relaxed_ion) but also give the pure electronic contribution, so that you can separate the parts.

Returns:

The clamped ion and relaxed ion data for the piezoelectric tensor.

Return type:

dict