SplitInterstitial¶
- class SplitInterstitial(interstitial_element, site_element, site_index, unit_cell_index=None, cartesian_coordinates=None, fractional_coordinates=None)¶
Data structure for a split interstitial (dumbbell) defect. This class only holds information and does not check for physical validity, which is imposed by
SplitInterstitialList
during dumbbell generation. The two sets ofcartesian_coordinates
(orfractional_coordinates
) are symmetric with respect tosite_index
.- Parameters:
interstitial_element (
PeriodicTableElement
) – The element to add at the given positions.site_element (
PeriodicTableElement
) – The lattice site displaced by the an interstitial element.site_index (int) – The index of the atom in the bulk unit cell configuration to be substituted with a split interstitial defect. Default:
0
unit_cell_index (sequence on int (size 3)) – The index of the unit cell in the infinite crystal which the reference site belongs to. substituted with a split interstitial defect. Default:
(0, 0, 0)
cartesian_coordinates (PhysicalQuantity of type length (size 2x3) | None) – Positions at which to insert two atoms of the split interstitial defect, given in absolute coordinates. This option is mutually exclusive to
fractional_coordinates
. Default: Nonefractional_coordinates (numpy.array (size 2x3) | None) – Positions at which to insert two atoms of the split interstitial defect, given in fractional coordinates of the bulk unit cell. This option is mutually exclusive to
cartesian_coordinates
. Default: None
- cartesianCoordinates()¶
- Returns:
The coordinates of the split interstitial defect as Cartesian coordinates if they have been specified, otherwise returns None.
- Return type:
PhysicalQuantity of type length (size 2x3) | None
- defectList()¶
- Returns:
The list of constituent defects.
- Return type:
list of [
Vacancy
|Substitutional
|Interstitial
]
- element()¶
- Returns:
The interstitial element used in the split-interstitial defect.
- Return type:
int
- fractionalCoordinates()¶
- Returns:
The coordinates of the split interstitial defect as fractional coordinates if they have been specified, otherwise returns None.
- Return type:
numpy.array (size 2x3) | None
- generateDefectConfiguration(reference_bulk_configuration, supercell_repetitions, use_ghost=None)¶
Generate the supercell with the embedded defect.
- Parameters:
reference_bulk_configuration (
BulkConfiguration
) – The bulk unit cell configuration.supercell_repetitions (sequence (size 3) of int) – The number of repetitions of the bulk unit cell along the (a, b, c) directions.
use_ghost (bool) – Whether to use a ghost atom at the vacancy defect site (not referenced for other types of defects).
- Returns:
The supercell configuration with the embedded defect.
- Return type:
- siteIndex()¶
- Returns:
Index of the site being replaced by a split interstitial defect
- Return type:
int
- uniqueString()¶
Return a unique string representing the state of the object.
Notes¶
A split interstitial is a type of defect occurring in solids. It is created by introducing an
impurity interstitial_element
that displaces an atom of the lattice.
The pair of impurity and displaced atom is commonly referred to as a dumbbell for
its resemblance to the weight-lifting device, as seen in Fig. 172.
A SplitInterstitial can be added to a NamedPointDefect to define a defect for use in a ChargedPointDefectConfiguration calculation.