Stress¶

class Stress(configuration, fix_strain=None)¶

Class for calculating the stress of a configuration.

Parameters:	configuration (BulkConfiguration) – Configuration with a calculator that supports stress calculations. fix_strain (FixStrain | None) – Additional constraint parameter. Default: None

evaluate()¶

Returns:	The stress for the given configuration. The shape of the stress tensor is (3,3).
Return type:	PhysicalQuantity with the unit eV * Angstrom**-3

metatext()¶

Returns:	The metatext of the object or None if no metatext is present.
Return type:	str | unicode | None

nlprint(stream=None)¶

Print a string containing an ASCII table useful for plotting the AnalysisSpin object.

Parameters:	stream (python stream) – The stream the table should be written to. Default: NLPrintLogger()

setMetatext(metatext)¶

Set a given metatext string on the object.

Parameters:	metatext (str | unicode | None) – The metatext string that should be set. A value of “None” can be given to remove the current metatext.

# Set up configuration
bulk_configuration = BulkConfiguration(
    bravais_lattice=FaceCenteredCubic(5.4*Angstrom),
    elements=[Gallium, Arsenic],
    cartesian_coordinates=[[ 0.      ,  0.      ,  0.      ],
                         [ 1.413425,  1.413425,  1.413425]]*Angstrom
    )

calculator = LCAOCalculator(
    numerical_accuracy_parameters=NumericalAccuracyParameters(
    k_point_sampling=(4, 4, 4))
    )

bulk_configuration.setCalculator(calculator)

#calculate the stress
stress = Stress(bulk_configuration)
nlprint(stress)