pyspinw.lattice_distances#

Calculations for finding distances between sites in a lattice

Functions

demo_point_finding()

Demonstrate the calculation of the calculation of cells for searching in

find_relative_positions(...[, tol, ...])

Find fractional coordinates from translations of the unit cell close to the origin.

full_search_space(unit_cell_transform, radius)

List of unit cell translations so that cells cover a sphere of the specified radius

partial_search_space(unit_cell_transform, radius)

Partial list of unit cell translations so that cells cover a sphere of the specified radius

Classes

InteractionGeometries(cell_indices, vectors, ...)

Holds the output from the algorithm to find relative positions
class pyspinw.lattice_distances.InteractionGeometries(cell_indices: ndarray, vectors: ndarray, distances: ndarray)#

Bases: object

Holds the output from the algorithm to find relative positions

cell_indices: ndarray#

Indices of the cells where a point was found at a sufficiently close distance

distances: ndarray#

Distance to the each point

expand() → list[tuple[ndarray, ndarray, ndarray]]#

Create a list of tuples from the data in this object

vectors: ndarray#

Vectors for each position found

pyspinw.lattice_distances.demo_point_finding()#

Demonstrate the calculation of the calculation of cells for searching in

pyspinw.lattice_distances.find_relative_positions(fractional_coordinates: ndarray, unit_cell_transform: ndarray, max_distance: float, tol: float = 1e-10, is_self_interaction=True) → InteractionGeometries#

Find fractional coordinates from translations of the unit cell close to the origin.

Find all sets of fractional coordinates produced by translations of input coordinates by multiples of the unit cell, and that differ by a cartesian distance of a most max_distance from (0,0,0)

Parameters:

  • fractional_coordinates – Fractional coordinates of the base point

  • unit_cell_transform – Transform from fractional coordinates to cartesian coordinates

  • max_distance – Maximum distance

  • tol – tolerance used to check for identity

  • is_self_interaction – include the original point with no translation (i,j,k = 0,0,0)

pyspinw.lattice_distances.full_search_space(unit_cell_transform: ndarray, radius: float) → ndarray#

List of unit cell translations so that cells cover a sphere of the specified radius

Parameters:

  • unit_cell_transform – transformation from fractional coordinates to cartesian coordinates

  • radius – maximum radius

pyspinw.lattice_distances.partial_search_space(unit_cell_transform: ndarray, radius: float) → ndarray#

Partial list of unit cell translations so that cells cover a sphere of the specified radius

Only one representation from each pair where (a,b,c) = (-p,-q,-r)

Parameters:

  • unit_cell_transform – transformation from fractional coordinates to cartesian coordinates

  • radius – maximum radius