1
|
|
|
"""Implements the :class:`PeriodicSet` class representing a periodic |
2
|
|
|
set, defined by a motif and unit cell. This models a crystal with a |
3
|
|
|
point at the center of each atom. |
4
|
|
|
|
5
|
|
|
This is the type yielded by :class:`amd.CifReader <.io.CifReader>` and |
6
|
|
|
:class:`amd.CSDReader <.io.CSDReader>`. A :class:`PeriodicSet` can be |
7
|
|
|
passed 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 __future__ import annotations |
12
|
|
|
from typing import Optional |
13
|
|
|
|
14
|
|
|
import numpy as np |
15
|
|
|
|
16
|
|
|
from .utils import ( |
17
|
|
|
cellpar_to_cell, |
18
|
|
|
cellpar_to_cell_2D, |
19
|
|
|
random_cell, |
20
|
|
|
) |
21
|
|
|
|
22
|
|
|
__all__ = ['PeriodicSet'] |
23
|
|
|
|
24
|
|
|
|
25
|
|
|
class PeriodicSet: |
26
|
|
|
"""A periodic set is a collection of points (motif) which |
27
|
|
|
periodically repeats according to a lattice (unit cell), often |
28
|
|
|
representing a crystal. |
29
|
|
|
|
30
|
|
|
:class:`PeriodicSet` s are returned by the readers in the |
31
|
|
|
:mod:`.io` module. They can be passed to |
32
|
|
|
:func:`amd.AMD() <.calculate.AMD>` or |
33
|
|
|
:func:`amd.PDD() <.calculate.PDD>` to calculate their invariants. |
34
|
|
|
|
35
|
|
|
Parameters |
36
|
|
|
---------- |
37
|
|
|
motif : :class:`numpy.ndarray` |
38
|
|
|
Cartesian (orthogonal) coordinates of the motif, shape (no |
39
|
|
|
points, dims). |
40
|
|
|
cell : :class:`numpy.ndarray` |
41
|
|
|
Cartesian (orthogonal) square array representing the unit cell, |
42
|
|
|
shape (dims, dims). Use |
43
|
|
|
:func:`amd.cellpar_to_cell <.utils.cellpar_to_cell>` to convert |
44
|
|
|
6 cell parameters to an orthogonal square matrix. |
45
|
|
|
name : str, optional |
46
|
|
|
Name of the periodic set. |
47
|
|
|
asym_unit : :class:`numpy.ndarray`, optional |
48
|
|
|
Indices for the asymmetric unit, pointing to the motif. Used in |
49
|
|
|
calculating AMD and PDD. |
50
|
|
|
multiplicities : :class:`numpy.ndarray`, optional |
51
|
|
|
Wyckoff multiplicities of points in the asymmetric unit, number |
52
|
|
|
of unique sites generated under symmetries. |
53
|
|
|
types : :class:`numpy.ndarray`, optional |
54
|
|
|
Array of atomic numbers of motif points. |
55
|
|
|
""" |
56
|
|
|
|
57
|
|
|
def __init__( |
58
|
|
|
self, |
59
|
|
|
motif: np.ndarray, |
60
|
|
|
cell: np.ndarray, |
61
|
|
|
name: Optional[str] = None, |
62
|
|
|
asym_unit: Optional[np.ndarray] = None, |
63
|
|
|
multiplicities: Optional[np.ndarray] = None, |
64
|
|
|
types: Optional[np.ndarray] = None |
65
|
|
|
): |
66
|
|
|
self.motif = motif |
67
|
|
|
self.cell = cell |
68
|
|
|
self.name = name |
69
|
|
|
self.asym_unit = asym_unit |
70
|
|
|
self.multiplicities = multiplicities |
71
|
|
|
self.types = types |
72
|
|
|
|
73
|
|
|
@property |
74
|
|
|
def ndim(self) -> int: |
75
|
|
|
return self.cell.shape[0] |
76
|
|
|
|
77
|
|
|
def __str__(self): |
78
|
|
|
m, n = self.motif.shape |
79
|
|
|
m_pl = '' if m == 1 else 's' |
80
|
|
|
n_pl = '' if n == 1 else 's' |
81
|
|
|
name_str = f'{self.name}: ' if self.name is not None else '' |
82
|
|
|
return f'PeriodicSet({name_str}{m} point{m_pl} in {n} dimension{n_pl})' |
83
|
|
|
|
84
|
|
|
def __repr__(self): |
85
|
|
|
|
86
|
|
|
motif_str = str(self.motif).replace('\n ', '\n' + ' ' * 11) |
87
|
|
|
cell_str = str(self.cell).replace('\n ', '\n' + ' ' * 10) |
88
|
|
|
optional_attrs = [] |
89
|
|
|
for attr in ('asym_unit', 'multiplicities', 'types'): |
90
|
|
|
val = getattr(self, attr) |
91
|
|
|
if val is not None: |
92
|
|
|
st = str(val).replace('\n ', '\n' + ' ' * (len(attr) + 6)) |
93
|
|
|
optional_attrs.append(f'{attr}={st}') |
94
|
|
|
optional_attrs_str = ',\n ' if optional_attrs else '' |
95
|
|
|
optional_attrs_str += ',\n '.join(optional_attrs) |
96
|
|
|
|
97
|
|
|
return ( |
98
|
|
|
f'PeriodicSet(name={self.name},\n' |
99
|
|
|
f' motif={motif_str},\n' |
100
|
|
|
f' cell={cell_str}{optional_attrs_str})' |
101
|
|
|
) |
102
|
|
|
|
103
|
|
|
def _equal_cell_and_motif(self, other): |
104
|
|
|
"""Used for debugging/tests. True if both 1. the unit cells are |
105
|
|
|
(close to) identical, and 2. the motifs are the same shape, and |
106
|
|
|
every point in one motif has a (close to) identical point |
107
|
|
|
somewhere in the other, accounting for pbc. |
108
|
|
|
""" |
109
|
|
|
|
110
|
|
|
tol = 1e-8 |
111
|
|
|
if self.cell.shape != other.cell.shape or \ |
112
|
|
|
self.motif.shape != other.motif.shape or \ |
113
|
|
|
not np.allclose(self.cell, other.cell): |
114
|
|
|
return False |
115
|
|
|
|
116
|
|
|
cell_inv = np.linalg.inv(self.cell) |
117
|
|
|
fm1 = np.mod(self.motif @ cell_inv, 1) |
118
|
|
|
fm2 = np.mod(other.motif @ cell_inv, 1) |
119
|
|
|
d1 = np.abs(fm2[:, None] - fm1) |
120
|
|
|
d2 = np.abs(d1 - 1) |
121
|
|
|
diffs = np.amax(np.minimum(d1, d2), axis=-1) |
122
|
|
|
|
123
|
|
|
if not np.all( |
124
|
|
|
(np.amin(diffs, axis=0) <= tol) | (np.amin(diffs, axis=-1) <= tol) |
125
|
|
|
): |
126
|
|
|
return False |
127
|
|
|
|
128
|
|
|
return True |
129
|
|
|
|
130
|
|
|
@staticmethod |
131
|
|
|
def cubic(scale: float = 1.0, dims: int = 3) -> PeriodicSet: |
132
|
|
|
"""Returns a :class:`PeriodicSet` representing a cubic lattice. |
133
|
|
|
""" |
134
|
|
|
return PeriodicSet(np.zeros((1, dims)), np.identity(dims) * scale) |
135
|
|
|
|
136
|
|
|
@staticmethod |
137
|
|
|
def hexagonal(scale: float = 1.0, dims: int = 3) -> PeriodicSet: |
138
|
|
|
""" Return a :class:`PeriodicSet` representing a hexagonal |
139
|
|
|
lattice. Dimensions 2 and 3 only. |
140
|
|
|
""" |
141
|
|
|
|
142
|
|
|
if dims == 3: |
143
|
|
|
cellpar = np.array([scale, scale, scale, 90.0, 90.0, 120.0]) |
144
|
|
|
cell = cellpar_to_cell(cellpar) |
145
|
|
|
elif dims == 2: |
146
|
|
|
cell = cellpar_to_cell_2D(np.array([scale, scale, 60.0])) |
147
|
|
|
else: |
148
|
|
|
raise NotImplementedError( |
149
|
|
|
'amd.PeriodicSet.hexagonal() only implemented for dimensions ' |
150
|
|
|
f'2 and 3, passed {dims}' |
151
|
|
|
) |
152
|
|
|
return PeriodicSet(np.zeros((1, dims)), cell) |
153
|
|
|
|
154
|
|
|
@staticmethod |
155
|
|
|
def _random( |
156
|
|
|
n_points: int, |
157
|
|
|
length_bounds: tuple = (1.0, 2.0), |
158
|
|
|
angle_bounds: tuple = (60.0, 120.0), |
159
|
|
|
dims: int = 3 |
160
|
|
|
) -> PeriodicSet: |
161
|
|
|
"""Return a :class:`PeriodicSet` with a chosen number of |
162
|
|
|
randomly placed points, in a random cell with edges between |
163
|
|
|
``length_bounds`` and angles between ``angle_bounds``. |
164
|
|
|
Dimensions 2 and 3 only. |
165
|
|
|
""" |
166
|
|
|
|
167
|
|
|
cell = random_cell( |
168
|
|
|
length_bounds=length_bounds, angle_bounds=angle_bounds, dims=dims |
169
|
|
|
) |
170
|
|
|
frac_motif = np.random.uniform(size=(n_points, dims)) |
171
|
|
|
return PeriodicSet(frac_motif @ cell, cell) |
172
|
|
|
|
173
|
|
|
|
174
|
|
|
|