Source code for wulfric.cell._sc_examples

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# Wulfric - Cell, Atoms, K-path, visualization.
# Copyright (C) 2023 Andrey Rybakov
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# e-mail: anry@uv.es, web: adrybakov.com
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from math import cos
from math import pi as PI
from math import sin, sqrt

import numpy as np

from wulfric.cell._basic_manipulation import from_params, get_reciprocal
from wulfric.constants._numerical import TORADIANS
from wulfric.constants._sc_convention import SC_BRAVAIS_LATTICE_VARIATIONS

__all__ = [
    "SC_CUB",
    "SC_FCC",
    "SC_BCC",
    "SC_TET",
    "SC_BCT",
    "SC_ORC",
    "SC_ORCF",
    "SC_ORCI",
    "SC_ORCC",
    "SC_HEX",
    "SC_RHL",
    "SC_MCL",
    "SC_MCLC",
    "SC_TRI",
    "sc_get_example",
]


# Primitive cell`s construction
[docs] def SC_CUB(a: float): r""" Constructs primitive cubic cell as defined in [1]_. .. math:: \begin{matrix} \boldsymbol{a}_1 &=& (a, &0, &0)\\ \boldsymbol{a}_2 &=& (0, &a, &0)\\ \boldsymbol{a}_3 &=& (0, &0, &a) \end{matrix} Parameters ---------- a : float or int Length of the three lattice vectors of the conventional cell. Returns ------- cell : (3, 3) :numpy:`ndarray` Matrix of a primitive cell, rows are interpreted as vectors. .. code-block:: python cell = [ [a1_x, a1_y, a1_z], [a2_x, a2_y, a2_z], [a3_x, a3_y, a3_z], ] References ---------- .. [1] Setyawan, W. and Curtarolo, S., 2010. High-throughput electronic band structure calculations: Challenges and tools. Computational materials science, 49(2), pp. 299-312. Examples -------- .. doctest:: >>> import wulfric >>> wulfric.cell.SC_CUB(a=2) array([[2, 0, 0], [0, 2, 0], [0, 0, 2]]) """ return np.array([[a, 0, 0], [0, a, 0], [0, 0, a]])
[docs] def SC_FCC(a: float): r""" Constructs primitive face-centred cubic cell as defined in [1]_. .. math:: \begin{matrix} \boldsymbol{a}_1 &=& (0, &a/2, &a/2)\\ \boldsymbol{a}_2 &=& (a/2, &0, &a/2)\\ \boldsymbol{a}_3 &=& (a/2, &a/2, &0) \end{matrix} Parameters ---------- a : float Length of the three lattice vectors of the conventional cell. Returns ------- cell : (3, 3) :numpy:`ndarray` Matrix of a primitive cell, rows are interpreted as vectors. .. code-block:: python cell = [ [a1_x, a1_y, a1_z], [a2_x, a2_y, a2_z], [a3_x, a3_y, a3_z], ] References ---------- .. [1] Setyawan, W. and Curtarolo, S., 2010. High-throughput electronic band structure calculations: Challenges and tools. Computational materials science, 49(2), pp. 299-312. Examples -------- .. doctest:: >>> import wulfric >>> wulfric.cell.SC_FCC(a=2) array([[0., 1., 1.], [1., 0., 1.], [1., 1., 0.]]) """ return np.array([[0, a / 2, a / 2], [a / 2, 0, a / 2], [a / 2, a / 2, 0]])
[docs] def SC_BCC(a: float): r""" Constructs primitive body-centred cubic cell as defined in [1]_. .. math:: \begin{matrix} \boldsymbol{a}_1 &=& (-a/2,& a/2,& a/2)\\ \boldsymbol{a}_2 &=& (a/2, &-a/2,& a/2)\\ \boldsymbol{a}_3 &=& (a/2, &a/2, &-a/2) \end{matrix} Parameters ---------- a : float Length of the three lattice vectors of the conventional cell. Returns ------- cell : (3, 3) :numpy:`ndarray` Matrix of a primitive cell, rows are interpreted as vectors. .. code-block:: python cell = [ [a1_x, a1_y, a1_z], [a2_x, a2_y, a2_z], [a3_x, a3_y, a3_z], ] References ---------- .. [1] Setyawan, W. and Curtarolo, S., 2010. High-throughput electronic band structure calculations: Challenges and tools. Computational materials science, 49(2), pp. 299-312. Examples -------- .. doctest:: >>> import wulfric >>> wulfric.cell.SC_BCC(a=2) array([[-1., 1., 1.], [ 1., -1., 1.], [ 1., 1., -1.]]) """ return np.array( [[-a / 2, a / 2, a / 2], [a / 2, -a / 2, a / 2], [a / 2, a / 2, -a / 2]] )
[docs] def SC_TET(a: float, c: float): r""" Constructs primitive tetragonal cell as defined in [1]_. .. math:: \begin{matrix} \boldsymbol{a}_1 &=& (a, &0, &0)\\ \boldsymbol{a}_2 &=& (0, &a, &0)\\ \boldsymbol{a}_3 &=& (0, &0, &c) \end{matrix} Parameters ---------- a : float Length of the first two lattice vectors of the conventional cell. c : float Length of the third lattice vector of the conventional cell. Returns ------- cell : (3, 3) :numpy:`ndarray` Matrix of a primitive cell, rows are interpreted as vectors. .. code-block:: python cell = [ [a1_x, a1_y, a1_z], [a2_x, a2_y, a2_z], [a3_x, a3_y, a3_z], ] References ---------- .. [1] Setyawan, W. and Curtarolo, S., 2010. High-throughput electronic band structure calculations: Challenges and tools. Computational materials science, 49(2), pp. 299-312. Examples -------- .. doctest:: >>> import wulfric >>> wulfric.cell.SC_TET(a=2, c=5) array([[2, 0, 0], [0, 2, 0], [0, 0, 5]]) """ return np.array([[a, 0, 0], [0, a, 0], [0, 0, c]])
[docs] def SC_BCT(a: float, c: float): r""" Constructs primitive body-centred tetragonal cell as defined in [1]_. .. math:: \begin{matrix} \boldsymbol{a}_1 &=& (-a/2, &a/2, &c/2)\\ \boldsymbol{a}_2 &=& (a/2, &-a/2, &c/2)\\ \boldsymbol{a}_3 &=& (a/2, &a/2, &-c/2) \end{matrix} Parameters ---------- a : float Length of the first two lattice vectors of the conventional cell. c : float Length of the third lattice vector of the conventional cell. Returns ------- cell : (3, 3) :numpy:`ndarray` Matrix of a primitive cell, rows are interpreted as vectors. .. code-block:: python cell = [ [a1_x, a1_y, a1_z], [a2_x, a2_y, a2_z], [a3_x, a3_y, a3_z], ] References ---------- .. [1] Setyawan, W. and Curtarolo, S., 2010. High-throughput electronic band structure calculations: Challenges and tools. Computational materials science, 49(2), pp. 299-312. Examples -------- .. doctest:: >>> import wulfric >>> wulfric.cell.SC_BCT(a=2, c=5) array([[-1. , 1. , 2.5], [ 1. , -1. , 2.5], [ 1. , 1. , -2.5]]) """ return np.array( [[-a / 2, a / 2, c / 2], [a / 2, -a / 2, c / 2], [a / 2, a / 2, -c / 2]] )
[docs] def SC_ORC(a: float, b: float, c: float): r""" Constructs primitive orthorhombic cell as defined in [1]_. .. math:: \begin{matrix} \boldsymbol{a}_1 &=& (a, &0, &0)\\ \boldsymbol{a}_2 &=& (0, &b, &0)\\ \boldsymbol{a}_3 &=& (0, &0, &c) \end{matrix} Input values are used as they are, therefore, the cell might not be a standard primitive one. Parameters ---------- a : float Length of the first lattice vector of the conventional cell. b : float Length of the second lattice vector of the conventional cell. c : float Length of the third lattice vector of the conventional cell. Returns ------- cell : (3, 3) :numpy:`ndarray` Matrix of a primitive cell, rows are interpreted as vectors. .. code-block:: python cell = [ [a1_x, a1_y, a1_z], [a2_x, a2_y, a2_z], [a3_x, a3_y, a3_z], ] References ---------- .. [1] Setyawan, W. and Curtarolo, S., 2010. High-throughput electronic band structure calculations: Challenges and tools. Computational materials science, 49(2), pp. 299-312. Examples -------- .. doctest:: >>> import wulfric >>> wulfric.cell.SC_ORC(a=3, b=5, c=7) array([[3, 0, 0], [0, 5, 0], [0, 0, 7]]) """ return np.array([[a, 0, 0], [0, b, 0], [0, 0, c]])
[docs] def SC_ORCF(a: float, b: float, c: float): r""" Constructs primitive face-centred orthorhombic cell as defined in [1]_. .. math:: \begin{matrix} \boldsymbol{a}_1 &=& (0, &b/2, &c/2)\\ \boldsymbol{a}_2 &=& (a/2, &0, &c/2)\\ \boldsymbol{a}_3 &=& (a/2, &b/2, &0) \end{matrix} Input values are used as they are, therefore, the cell might not be a standard primitive one. Parameters ---------- a : float Length of the first lattice vector of the conventional cell. b : float Length of the second lattice vector of the conventional cell. c : float Length of the third lattice vector of the conventional cell. Returns ------- cell : (3, 3) :numpy:`ndarray` Matrix of a primitive cell, rows are interpreted as vectors. .. code-block:: python cell = [ [a1_x, a1_y, a1_z], [a2_x, a2_y, a2_z], [a3_x, a3_y, a3_z], ] References ---------- .. [1] Setyawan, W. and Curtarolo, S., 2010. High-throughput electronic band structure calculations: Challenges and tools. Computational materials science, 49(2), pp. 299-312. Examples -------- .. doctest:: >>> import wulfric >>> wulfric.cell.SC_ORCF(a=3, b=5, c=7) array([[0. , 2.5, 3.5], [1.5, 0. , 3.5], [1.5, 2.5, 0. ]]) """ return np.array([[0, b / 2, c / 2], [a / 2, 0, c / 2], [a / 2, b / 2, 0]])
[docs] def SC_ORCI(a: float, b: float, c: float): r""" Constructs primitive body-centred orthorhombic cell as defined in [1]_. .. math:: \begin{matrix} \boldsymbol{a}_1 &=& (-a/2, &b/2, &c/2)\\ \boldsymbol{a}_2 &=& (a/2, &-b/2, &c/2)\\ \boldsymbol{a}_3 &=& (a/2, &b/2, &-c/2) \end{matrix} Input values are used as they are, therefore, the cell might not be a standard primitive one. Parameters ---------- a : float Length of the first lattice vector of the conventional cell. b : float Length of the second lattice vector of the conventional cell. c : float Length of the third lattice vector of the conventional cell. Returns ------- cell : (3, 3) :numpy:`ndarray` Matrix of a primitive cell, rows are interpreted as vectors. .. code-block:: python cell = [ [a1_x, a1_y, a1_z], [a2_x, a2_y, a2_z], [a3_x, a3_y, a3_z], ] References ---------- .. [1] Setyawan, W. and Curtarolo, S., 2010. High-throughput electronic band structure calculations: Challenges and tools. Computational materials science, 49(2), pp. 299-312. Examples -------- .. doctest:: >>> import wulfric >>> wulfric.cell.SC_ORCI(a=3, b=5, c=7) array([[-1.5, 2.5, 3.5], [ 1.5, -2.5, 3.5], [ 1.5, 2.5, -3.5]]) """ return np.array( [[-a / 2, b / 2, c / 2], [a / 2, -b / 2, c / 2], [a / 2, b / 2, -c / 2]] )
[docs] def SC_ORCC(a: float, b: float, c: float): r""" Constructs primitive base-centred orthorhombic cell as defined in [1]_. .. math:: \begin{matrix} \boldsymbol{a}_1 &=& (a/2, &-b/2, &0)\\ \boldsymbol{a}_2 &=& (a/2, &b/2, &0)\\ \boldsymbol{a}_3 &=& (0, &0, &c) \end{matrix} Input values are used as they are, therefore, the cell might not be a standard primitive one. Parameters ---------- a : float Length of the first lattice vector of the conventional cell. b : float Length of the second lattice vector of the conventional cell. c : float Length of the third lattice vector of the conventional cell. Returns ------- cell : (3, 3) :numpy:`ndarray` Matrix of a primitive cell, rows are interpreted as vectors. .. code-block:: python cell = [ [a1_x, a1_y, a1_z], [a2_x, a2_y, a2_z], [a3_x, a3_y, a3_z], ] References ---------- .. [1] Setyawan, W. and Curtarolo, S., 2010. High-throughput electronic band structure calculations: Challenges and tools. Computational materials science, 49(2), pp. 299-312. Examples -------- .. doctest:: >>> import wulfric >>> wulfric.cell.SC_ORCC(a=3, b=5, c=7) array([[ 1.5, -2.5, 0. ], [ 1.5, 2.5, 0. ], [ 0. , 0. , 7. ]]) """ return np.array([[a / 2, -b / 2, 0], [a / 2, b / 2, 0], [0, 0, c]])
[docs] def SC_HEX(a: float, c: float): r""" Constructs primitive hexagonal cell as defined in [1]_. .. math:: \begin{matrix} \boldsymbol{a}_1 &=& (\frac{a}{2}, &\frac{-a\sqrt{3}}{2}, &0)\\ \boldsymbol{a}_2 &=& (\frac{a}{2}, &\frac{a\sqrt{3}}{2}, &0)\\ \boldsymbol{a}_3 &=& (0, &0, &c) \end{matrix} Parameters ---------- a : float Length of the first two lattice vectors of the conventional cell. c : float Length of the third lattice vector of the conventional cell. Returns ------- cell : (3, 3) :numpy:`ndarray` Matrix of a primitive cell, rows are interpreted as vectors. .. code-block:: python cell = [ [a1_x, a1_y, a1_z], [a2_x, a2_y, a2_z], [a3_x, a3_y, a3_z], ] References ---------- .. [1] Setyawan, W. and Curtarolo, S., 2010. High-throughput electronic band structure calculations: Challenges and tools. Computational materials science, 49(2), pp. 299-312. Examples -------- .. doctest:: >>> import wulfric >>> wulfric.cell.SC_HEX(a=3, c=5) array([[ 1.5 , -2.59807621, 0. ], [ 1.5 , 2.59807621, 0. ], [ 0. , 0. , 5. ]]) """ return np.array( [[a / 2, -a * sqrt(3) / 2, 0], [a / 2, a * sqrt(3) / 2, 0], [0, 0, c]] )
[docs] def SC_RHL(a: float, alpha: float): r""" Constructs primitive rhombohedral cell as defined in [1]_. .. math:: \begin{matrix} \boldsymbol{a}_1 &=& (a\cos(\alpha / 2), &-a\sin(\alpha/2), &0)\\ \boldsymbol{a}_2 &=& (a\cos(\alpha / 2), &a\sin(\alpha/2), &0)\\ \boldsymbol{a}_3 &=& \left(\dfrac{\cos\alpha}{\cos(\alpha/2)}\right., &0, &\left.a\sqrt{1 - \dfrac{\cos^2\alpha}{\cos^2(\alpha/2)}}\right) \end{matrix} Input values are used as they are, therefore, the cell might not be a standard primitive one. Parameters ---------- a : float Length of the lattice vectors of the conventional cell. alpha : float Angle between vectors :math:`a_2` and :math:`a_3` of the conventional cell in degrees. Returns ------- cell : (3, 3) :numpy:`ndarray` Matrix of a primitive cell, rows are interpreted as vectors. .. code-block:: python cell = [ [a1_x, a1_y, a1_z], [a2_x, a2_y, a2_z], [a3_x, a3_y, a3_z], ] References ---------- .. [1] Setyawan, W. and Curtarolo, S., 2010. High-throughput electronic band structure calculations: Challenges and tools. Computational materials science, 49(2), pp. 299-312. Examples -------- .. doctest:: >>> import wulfric >>> wulfric.cell.SC_RHL(a=3, alpha=40) array([[ 2.81907786, -1.02606043, 0. ], [ 2.81907786, 1.02606043, 0. ], [ 2.44562241, 0. , 1.73750713]]) """ alpha *= TORADIANS return np.array( [ [a * cos(alpha / 2), -a * sin(alpha / 2), 0], [a * cos(alpha / 2), a * sin(alpha / 2), 0], [ a * cos(alpha) / cos(alpha / 2), 0, a * sqrt(1 - cos(alpha) ** 2 / cos(alpha / 2) ** 2), ], ] )
[docs] def SC_MCL(a: float, b: float, c: float, alpha: float): r""" Constructs primitive monoclinic cell as defined in [1]_. .. math:: \begin{matrix} \boldsymbol{a}_1 &=& (a, &0, &0)\\ \boldsymbol{a}_2 &=& (0, &b, &0)\\ \boldsymbol{a}_3 &=& (0, &c\cos\alpha, &c\sin\alpha) \end{matrix} Input values are used as they are, therefore, the cell might not be a standard primitive one. Parameters ---------- a : float Length of the first lattice vector of the conventional cell. b : float Length of the second of the two remaining lattice vectors of the conventional cell. c : float Length of the third of the two remaining lattice vectors of the conventional cell. alpha : float Angle between vectors :math:`a_2` and :math:`a_3` of the conventional cell in degrees. Returns ------- cell : (3, 3) :numpy:`ndarray` Matrix of a primitive cell, rows are interpreted as vectors. .. code-block:: python cell = [ [a1_x, a1_y, a1_z], [a2_x, a2_y, a2_z], [a3_x, a3_y, a3_z], ] References ---------- .. [1] Setyawan, W. and Curtarolo, S., 2010. High-throughput electronic band structure calculations: Challenges and tools. Computational materials science, 49(2), pp. 299-312. Examples -------- .. doctest:: >>> import wulfric >>> wulfric.cell.SC_MCL(a=3, b=5, c=7, alpha=45) array([[3. , 0. , 0. ], [0. , 5. , 0. ], [0. , 4.94974747, 4.94974747]]) """ alpha *= TORADIANS return np.array([[a, 0, 0], [0, b, 0], [0, c * cos(alpha), c * sin(alpha)]])
[docs] def SC_MCLC(a: float, b: float, c: float, alpha: float): r""" Constructs primitive base-centred monoclinic cell as defined in [1]_. .. math:: \begin{matrix} \boldsymbol{a}_1 &=& (a/2, &b/2, &0)\\ \boldsymbol{a}_2 &=& (-a/2, &b/2, &0)\\ \boldsymbol{a}_3 &=& (0, &c\cos\alpha, &c\sin\alpha) \end{matrix} Input values are used as they are, therefore, the cell might not be a standard primitive one. Parameters ---------- a : float Length of the first lattice vector of the conventional cell. b : float Length of the second of the two remaining lattice vectors of the conventional cell. c : float Length of the third of the two remaining lattice vectors of the conventional cell. alpha : float Angle between vectors :math:`a_2` and :math:`a_3` of the conventional cell in degrees. Returns ------- cell : (3, 3) :numpy:`ndarray` Matrix of a primitive cell, rows are interpreted as vectors. .. code-block:: python cell = [ [a1_x, a1_y, a1_z], [a2_x, a2_y, a2_z], [a3_x, a3_y, a3_z], ] References ---------- .. [1] Setyawan, W. and Curtarolo, S., 2010. High-throughput electronic band structure calculations: Challenges and tools. Computational materials science, 49(2), pp. 299-312. Examples -------- .. doctest:: >>> import wulfric >>> wulfric.cell.SC_MCLC(a=3, b=5, c=7, alpha=45) array([[ 1.5 , 2.5 , 0. ], [-1.5 , 2.5 , 0. ], [ 0. , 4.94974747, 4.94974747]]) """ alpha *= TORADIANS return np.array( [ [a / 2, b / 2, 0], [-a / 2, b / 2, 0], [0, c * cos(alpha), c * sin(alpha)], ] )
[docs] def SC_TRI( a: float, b: float, c: float, alpha: float, beta: float, gamma: float, input_reciprocal=False, ): r""" Constructs primitive triclinic cell as defined in [1]_. .. math:: \begin{matrix} \boldsymbol{a}_1 &=& (a, &0, &0)\\ \boldsymbol{a}_2 &=& (b\cos\gamma, &b\sin\gamma, &0)\\ \boldsymbol{a}_3 &=& (c\cos\beta, &\dfrac{c(\cos\alpha - \cos\beta\cos\gamma)}{\sin\gamma}, &\dfrac{c}{\sin\gamma}\sqrt{\sin^2\gamma - \cos^2\alpha - \cos^2\beta + 2\cos\alpha\cos\beta\cos\gamma}) \end{matrix} Parameters ---------- a : float Length of the first lattice vector of the conventional cell. b : float Length of the second lattice vector of the conventional cell. c : float Length of the third lattice vector of the conventional cell. alpha : float Angle between vectors :math:`a_2` and :math:`a_3` of the conventional cell in degrees. beta : float Angle between vectors :math:`a_1` and :math:`a_3` of the conventional cell in degrees. gamma : float Angle between vectors :math:`a_1` and :math:`a_2` of the conventional cell in degrees. input_reciprocal : bool, default False Whether to interpret input as reciprocal parameters. Returns ------- cell : (3, 3) :numpy:`ndarray` Matrix of a primitive cell, rows are interpreted as vectors. .. code-block:: python cell = [ [a1_x, a1_y, a1_z], [a2_x, a2_y, a2_z], [a3_x, a3_y, a3_z], ] References ---------- .. [1] Setyawan, W. and Curtarolo, S., 2010. High-throughput electronic band structure calculations: Challenges and tools. Computational materials science, 49(2), pp. 299-312. Examples -------- .. doctest:: >>> import wulfric >>> wulfric.cell.SC_TRI(a=3, b=5, c=7, alpha=45, beta=33, gamma=21) array([[ 3. , 0. , 0. ], [ 4.66790213, 1.79183975, 0. ], [ 5.87069398, -1.48176621, 3.51273699]]) """ cell = from_params(a, b, c, alpha, beta, gamma) if input_reciprocal: cell = get_reciprocal(cell) return cell
[docs] def sc_get_example(lattice_variation: str = None): r""" Examples of the Bravais lattices as defined in the paper by Setyawan and Curtarolo [1]_. .. versionchanged:: 0.6.3 renamed from ``sc_get_example_cell``. Parameters ---------- lattice_variation : str, optional Name of the lattice type or variation to be returned. For available names see documentation of each :ref:`user-guide_conventions_bravais-lattices`. Case-insensitive. Returns ------- cell : (3, 3) :numpy:`ndarray` Matrix of a direct cell, rows are interpreted as vectors. .. code-block:: python cell = [ [a1_x, a1_y, a1_z], [a2_x, a2_y, a2_z], [a3_x, a3_y, a3_z], ] References ---------- .. [1] Setyawan, W. and Curtarolo, S., 2010. High-throughput electronic band structure calculations: Challenges and tools. Computational materials science, 49(2), pp. 299-312. Examples -------- .. doctest:: >>> import wulfric >>> wulfric.cell.sc_get_example("cub") array([[3.14159265, 0. , 0. ], [0. , 3.14159265, 0. ], [0. , 0. , 3.14159265]]) >>> wulfric.cell.sc_get_example("ORCF3") array([[0. , 1.96349541, 2.61799388], [1.57079633, 0. , 2.61799388], [1.57079633, 1.96349541, 0. ]]) """ correct_inputs = set(map(lambda x: x.lower(), SC_BRAVAIS_LATTICE_VARIATIONS)).union( set( map( lambda x: x.translate(str.maketrans("", "", "12345ab")).lower(), SC_BRAVAIS_LATTICE_VARIATIONS, ) ) ) if ( not isinstance(lattice_variation, str) or lattice_variation.lower() not in correct_inputs ): message = ( f'There is no example of "{lattice_variation}" Bravais lattice. ' "Available examples are:\n" ) for name in correct_inputs: message += f" * {name}\n" raise ValueError(message) lattice_variation = lattice_variation.lower() if lattice_variation == "cub": cell = SC_CUB(PI) elif lattice_variation == "fcc": cell = SC_FCC(PI) elif lattice_variation == "bcc": cell = SC_BCC(PI) elif lattice_variation == "tet": cell = SC_TET(PI, 1.5 * PI) elif lattice_variation in ["bct1", "bct"]: cell = SC_BCT(1.5 * PI, PI) elif lattice_variation == "bct2": cell = SC_BCT(PI, 1.5 * PI) elif lattice_variation == "orc": cell = SC_ORC(PI, 1.5 * PI, 2 * PI) elif lattice_variation in ["orcf1", "orcf"]: cell = SC_ORCF(0.7 * PI, 5 / 4 * PI, 5 / 3 * PI) elif lattice_variation == "orcf2": cell = SC_ORCF(1.2 * PI, 5 / 4 * PI, 5 / 3 * PI) elif lattice_variation == "orcf3": cell = SC_ORCF(PI, 5 / 4 * PI, 5 / 3 * PI) elif lattice_variation == "orci": return SC_ORCI(PI, 1.3 * PI, 1.7 * PI) elif lattice_variation == "orcc": cell = SC_ORCC(PI, 1.3 * PI, 1.7 * PI) elif lattice_variation == "hex": cell = SC_HEX(PI, 2 * PI) elif lattice_variation in ["rhl1", "rhl"]: # If alpha = 60 it is effectively FCC! cell = SC_RHL(PI, 70) elif lattice_variation == "rhl2": cell = SC_RHL(PI, 110) elif lattice_variation == "mcl": cell = SC_MCL(PI, 1.3 * PI, 1.6 * PI, alpha=75) elif lattice_variation in ["mclc1", "mclc"]: cell = SC_MCLC(PI, 1.4 * PI, 1.7 * PI, 80) elif lattice_variation == "mclc2": cell = SC_MCLC(1.4 * PI * sin(75 * TORADIANS), 1.4 * PI, 1.7 * PI, 75) elif lattice_variation == "mclc3": b = PI x = 1.1 alpha = 78 ralpha = alpha * TORADIANS c = b * (x**2) / (x**2 - 1) * cos(ralpha) * 1.8 a = x * b * sin(ralpha) cell = SC_MCLC(a, b, c, alpha) elif lattice_variation == "mclc4": b = PI x = 1.2 alpha = 65 ralpha = alpha * TORADIANS c = b * (x**2) / (x**2 - 1) * cos(ralpha) a = x * b * sin(ralpha) cell = SC_MCLC(a, b, c, alpha) elif lattice_variation == "mclc5": b = PI x = 1.4 alpha = 53 ralpha = alpha * TORADIANS c = b * (x**2) / (x**2 - 1) * cos(ralpha) * 0.9 a = x * b * sin(ralpha) cell = SC_MCLC(a, b, c, alpha) elif lattice_variation in ["tri1a", "tri1", "tri", "tria"]: cell = SC_TRI(0.5, 0.5, 0.5, 50.0, 60.0, 80.0) elif lattice_variation in ["tri2a", "tri2"]: cell = SC_TRI(0.5, 1.0, 1.0, 100.0, 100.0, 140.0) elif lattice_variation in ["tri1b", "trib"]: cell = SC_TRI(0.5, 1.0, 1.0, 100.0, 110.0, 60.0) elif lattice_variation == "tri2b": cell = SC_TRI(0.5, 1.0, 2.0, 80.0, 100.0, 40.0) return cell