1
|
|
|
"""Implements the :class:`PeriodicSet` class representing a periodic set, |
2
|
|
|
defined by a motif and unit cell. This models a crystal with a point at the |
3
|
|
|
center of each atom. |
4
|
|
|
|
5
|
|
|
This is the type yielded by the readers :class:`amd.CifReader <.io.CifReader>` |
|
|
|
|
6
|
|
|
and :class:`amd.CSDReader <.io.CSDReader>`. A :class:`PeriodicSet` can be passed |
|
|
|
|
7
|
|
|
as the first argument to :func:`amd.AMD() <.calculate.AMD>` or |
|
|
|
|
8
|
|
|
:func:`amd.PDD() <.calculate.PDD>` to calculate its invariants. |
9
|
|
|
""" |
10
|
|
|
|
11
|
|
|
from typing import Optional |
12
|
|
|
import numpy as np |
13
|
|
|
|
14
|
|
|
from .utils import ( |
15
|
|
|
cellpar_to_cell, |
16
|
|
|
cellpar_to_cell_2D, |
17
|
|
|
cell_to_cellpar, |
18
|
|
|
cell_to_cellpar_2D, |
19
|
|
|
random_cell, |
20
|
|
|
) |
21
|
|
|
|
22
|
|
|
|
23
|
|
|
class PeriodicSet: |
24
|
|
|
"""A periodic set is the mathematical representation of a crystal by putting a |
25
|
|
|
single point in the center of every atom. It is defined by a basis (unit cell) |
|
|
|
|
26
|
|
|
and collection of points (motif) which repeats according to the basis. |
27
|
|
|
|
28
|
|
|
:class:`PeriodicSet` s are returned by the readers in the :mod:`.io` module. |
29
|
|
|
They can be passed to :func:`amd.AMD() <.calculate.AMD>` or |
|
|
|
|
30
|
|
|
:func:`amd.PDD() <.calculate.PDD>` to calculate the invariants. |
31
|
|
|
|
32
|
|
|
Parameters |
33
|
|
|
---------- |
34
|
|
|
motif : :class:`numpy.ndarray` |
35
|
|
|
Cartesian (orthogonal) coordinates of the motif, shape (no points, dims). |
36
|
|
|
cell : :class:`numpy.ndarray` |
37
|
|
|
Cartesian (orthogonal) square array representing the unit cell, shape (dims, dims). |
38
|
|
|
Use :func:`amd.cellpar_to_cell <.utils.cellpar_to_cell>` to convert 6 cell |
|
|
|
|
39
|
|
|
parameters to an orthogonal square matrix. |
40
|
|
|
name : str, optional |
41
|
|
|
Name of the periodic set. |
42
|
|
|
asymmetric_unit : :class:`numpy.ndarray`, optional |
43
|
|
|
Indices for the asymmetric unit, pointing to the motif. |
44
|
|
|
wyckoff_multiplicities : :class:`numpy.ndarray`, optional |
45
|
|
|
Wyckoff multiplicities of each atom in the asymmetric unit |
46
|
|
|
(number of unique sites generated under all symmetries). |
47
|
|
|
types : :class:`numpy.ndarray`, optional |
48
|
|
|
Array of atomic numbers of motif points. |
49
|
|
|
""" |
50
|
|
|
|
51
|
|
|
def __init__( |
|
|
|
|
52
|
|
|
self, |
53
|
|
|
motif: np.ndarray, |
54
|
|
|
cell: np.ndarray, |
55
|
|
|
name: Optional[str] = None, |
56
|
|
|
asymmetric_unit: Optional[np.ndarray] = None, |
57
|
|
|
wyckoff_multiplicities: Optional[np.ndarray] = None, |
58
|
|
|
types : Optional[np.ndarray] = None |
|
|
|
|
59
|
|
|
): |
60
|
|
|
|
61
|
|
|
self.motif = motif |
62
|
|
|
self.cell = cell |
63
|
|
|
self.name = name |
64
|
|
|
self.asymmetric_unit = asymmetric_unit |
65
|
|
|
self.wyckoff_multiplicities = wyckoff_multiplicities |
66
|
|
|
self.types = types |
67
|
|
|
self.ndim = self.cell.shape[0] |
68
|
|
|
|
69
|
|
|
def __str__(self): |
70
|
|
|
return repr(self) |
71
|
|
|
|
72
|
|
|
def __repr__(self): |
73
|
|
|
|
74
|
|
|
if self.asymmetric_unit is None: |
75
|
|
|
n_asym_sites = len(self.motif) |
76
|
|
|
else: |
77
|
|
|
n_asym_sites = len(self.asymmetric_unit) |
78
|
|
|
|
79
|
|
|
s = f'PeriodicSet(name={self.name}, ' \ |
80
|
|
|
f'motif {self.motif.shape}, ' \ |
81
|
|
|
f'{n_asym_sites} asym sites' |
82
|
|
|
|
83
|
|
|
if self.cell.shape[0] == 2: |
84
|
|
|
cellpar = np.round(cell_to_cellpar_2D(self.cell), 2) |
85
|
|
|
cell_str = f'a={cellpar[0]}, b={cellpar[1]}, α={cellpar[2]}' |
86
|
|
|
s += ', ' + cell_str |
87
|
|
|
elif self.cell.shape[0] == 3: |
88
|
|
|
cellpar = np.round(cell_to_cellpar(self.cell), 2) |
89
|
|
|
cell_str = f'a={cellpar[0]}, b={cellpar[1]}, c={cellpar[2]}, ' \ |
90
|
|
|
f'α={cellpar[3]}, β={cellpar[4]}, γ={cellpar[5]}' |
91
|
|
|
s += ', ' + cell_str |
92
|
|
|
|
93
|
|
|
s += ')' |
94
|
|
|
|
95
|
|
|
return s |
96
|
|
|
|
|
|
|
|
97
|
|
|
# used for debugging, checks if the motif/cell agree point for point |
98
|
|
|
# (disregarding order), NOT up to isometry. |
99
|
|
|
def __eq__(self, other): |
100
|
|
|
|
101
|
|
|
if self.cell.shape != other.cell.shape or self.motif.shape != other.motif.shape: |
102
|
|
|
return False |
103
|
|
|
|
104
|
|
|
if not np.allclose(self.cell, other.cell): |
105
|
|
|
return False |
106
|
|
|
|
107
|
|
|
# needs fixing, currently only for tests/debugging. |
108
|
|
|
# doesn't even check if motifs are alike because pbcs may make them look different |
109
|
|
|
|
|
|
|
|
110
|
|
|
# m1 = np.mod(self.motif @ np.linalg.inv(self.cell), 1) |
111
|
|
|
# m2 = np.mod(other.motif @ np.linalg.inv(other.cell), 1) |
112
|
|
|
|
|
|
|
|
113
|
|
|
# diffs = np.amax(np.abs(m2[:, None] - m1), axis=-1) |
114
|
|
|
# if not np.all((np.amin(diffs, axis=0) <= 1e-8) | (np.amin(diffs, axis=-1) <= 1e-8)): |
115
|
|
|
# return False |
116
|
|
|
|
117
|
|
|
# diffs = np.amax(np.abs(other.motif[:, None] - self.motif), axis=-1) |
118
|
|
|
# if not np.all((np.amin(diffs, axis=0) <= 1e-6) | (np.amin(diffs, axis=-1) <= 1e-6)): |
119
|
|
|
# return False |
120
|
|
|
|
121
|
|
|
return True |
122
|
|
|
|
123
|
|
|
def __ne__(self, other): |
124
|
|
|
return not self.__eq__(other) |
125
|
|
|
|
126
|
|
|
|
127
|
|
|
|
128
|
|
|
@staticmethod |
129
|
|
|
def cubic(scale=1, dims=3): |
130
|
|
|
"""Return a :class:`PeriodicSet` representing a cubic lattice.""" |
131
|
|
|
cell = np.identity(dims) * scale |
132
|
|
|
return PeriodicSet(np.zeros((1, dims)), cell) |
133
|
|
|
|
134
|
|
|
@staticmethod |
135
|
|
|
def hexagonal(scale=1, dims=3): |
136
|
|
|
"""Dimensions 2 and 3 only. Return a :class:`PeriodicSet` representing a |
137
|
|
|
hexagonal lattice.""" |
138
|
|
|
if dims == 3: |
139
|
|
|
cell = cellpar_to_cell(scale, scale, scale, 90, 90, 120) |
140
|
|
|
elif dims == 2: |
141
|
|
|
cell = cellpar_to_cell_2D(scale, scale, 60) |
|
|
|
|
142
|
|
|
else: |
143
|
|
|
msg = f'hexagonal lattice only implemented for dimensions 2 and 3 (passed {dims})' |
144
|
|
|
raise NotImplementedError(msg) |
145
|
|
|
|
146
|
|
|
return PeriodicSet(np.zeros((1, dims)), cell) |
147
|
|
|
|
148
|
|
|
@staticmethod |
149
|
|
|
def _random(n_points, length_bounds=(1, 2), angle_bounds=(60, 120), dims=3): |
150
|
|
|
"""Dimensions 2 and 3 only. Return a :class:`PeriodicSet` with a chosen |
151
|
|
|
number of randomly placed points, in random cell with edges between |
|
|
|
|
152
|
|
|
length_bounds and angles between angle_bounds.""" |
153
|
|
|
cell = random_cell(length_bounds=length_bounds, angle_bounds=angle_bounds, dims=dims) |
154
|
|
|
frac_motif = np.random.uniform(size=(n_points, dims)) |
155
|
|
|
motif = frac_motif @ cell |
156
|
|
|
return PeriodicSet(motif, cell) |
157
|
|
|
|