-
Notifications
You must be signed in to change notification settings - Fork 1
/
moire_graphene_rhombus.py
537 lines (433 loc) · 17.4 KB
/
moire_graphene_rhombus.py
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
# ============================================================================= #
# Copyright (C) 2021 Soham Mandal #
# #
# This program is free software: you can redistribute it and/or modify #
# it under the terms of the GNU General Public License as published by #
# the Free Software Foundation, either version 3 of the License, or #
# (at your option) any later version. #
# #
# This program is distributed in the hope that it will be useful, #
# but WITHOUT ANY WARRANTY; without even the implied warranty of #
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the #
# GNU General Public License for more details. #
# #
# You should have received a copy of the GNU General Public License #
# along with this program. If not, see <https://www.gnu.org/licenses/>. #
# #
# e-mail: [email protected] #
# ============================================================================= #
import os.path
import sys
from termcolor import colored
import argparse
import numpy as np
from scipy.spatial import distance
import matplotlib.pyplot as plt
#####################################################################
def create_layer1(nx, ny, nx_ex, ny_ey, d_CC, Cz, lx, ly):
x1 = -lx * nx_ex
y1 = -ly * ny_ex
z1 = Cz
x2 = x1
y2 = y1 + d_CC
z2 = Cz
x3 = x2 + d_CC * np.cos(np.pi/6)
y3 = y2 + d_CC / 2
z3 = Cz
x4 = x3
y4 = y3 + d_CC
z4 = Cz
unit = np.array([[x4, y4, z4], [x3, y3, z3], [x2, y2, z2], [x1, y1, z1]], float)
N = ny*4*nx
Gr = np.zeros([N, 4], float)
Gr[(ny*4 - 4) : (ny*4),1:] = unit
Gr[(ny*4 - 4) : (ny*4), 0] = [1, 1, 1, 1]
y_incr = np.zeros([4, 4], float)
y_incr[:, 2] = ly
x_incr = np.zeros([ny*4, 4], float)
x_incr[:, 1] = lx
start_o = ny*4 - 4
end_o = ny*4
for i in range(ny - 1):
start_n = start_o - 4
end_n = start_o
Gr[start_n:end_n, :] = Gr[start_o:end_o, :] + y_incr
start_o = start_n
end_o = end_n
start_o = 0
end_o = ny * 4
for j in range(nx - 1):
start_n = end_o
end_n = start_n + ny*4
Gr[start_n:end_n, :] = Gr[start_o : end_o, :] + x_incr
start_o = start_n
end_o = end_n
return Gr
def create_bond(nx, ny):
atm = 0
count = 0
bond = np.zeros([ny*6*nx*6, 2], int)
for j in range(nx):
for i in range(ny-1):
bond[count, :] = [atm, atm+1]
count += 1
bond[count, :] = [atm+1, atm+2]
count += 1
bond[count, :] = [atm+2, atm+3]
count += 1
bond[count, :] = [atm+3, atm+4]
count += 1
atm += 4
bond[count, :] = [atm, atm+1]
count += 1
bond[count, :] = [atm+1, atm+2]
count += 1
bond[count, :] = [atm+2, atm+3]
count += 1
atm += 4
C1 = np.arange(1, ny*4, 4, int)
(C1_n, ) = C1.shape
C1_i = ny*4 + 1
C2 = np.arange(4, ny*4, 4, int)
(C2_n, ) = C2.shape
C2_i = ny*4 - 1
for j in range(nx-1):
C1_C = C1 + C1_i
bond[count:count+C1_n, 0] = C1
bond[count:count+C1_n, 1] = C1_C
count += C1_n
C2_C = C2 + C2_i
bond[count:count+C2_n, 0] = C2
bond[count:count+C2_n, 1] = C2_C
count += C2_n
C1 += ny*4
C2 += ny*4
bond = bond[:count, :]
return bond, count
def cs_theta(m, r, lx):
theta = np.arccos((3 * m*m + 3*m*r + 0.5 * r*r)/ (3 * m*m + 3*m*r + r*r)) * 180 / np.pi
print()
print("\tAngle of rotation (degree): ", theta)
a1_x = lx
a1_y = 0
a2_x = lx / 2
a2_y = lx * np.cos(np.pi/6)
a1 = np.array([a1_x, a1_y], float)
a2 = np.array([a2_x, a2_y], float)
if np.gcd(r, 3) == 1:
t1_x = m*a1_x + (m + r)*a2_x
t1_y = m*a1_y + (m + r)*a2_y
t2_x = -(m+r)*a1_x + (2*m + r)*a2_x
t2_y = -(m+r)*a1_y + (2*m + r)*a2_y
N = 4 * ((m+r)**2 + m*(2*m + r))
print("\tNumber of atoms in moire cell from formula: ", N)
elif np.gcd(r, 3) == 3:
t1_x = (m+(r//3))*a1_x + (r//3)*a2_x
t1_y = (m+(r//3))*a1_y + (r//3)*a2_y
t2_x = -(r//3)*a1_x + (m + 2*(r//3))*a2_x
t2_y = -(r//3)*a1_y + (m + 2*(r//3))*a2_y
N = 2*((m+r)**2) + m * (r + 3*m)
t1 = np.array([t1_x, t1_y], float)
t2 = np.array([t2_x, t2_y], float)
xv1 = 0
yv1 = 0
xv2 = t1_x
yv2 = t1_y
xv4 = t2_x
yv4 = t2_y
xv3 = xv2 + xv4
yv3 = yv2 + yv4
vertices = np.zeros([5, 2], float)
vertices[:, 0] = [xv1, xv2, xv3, xv4, xv1]
vertices[:, 1] = [yv1, yv2, yv3, yv4, yv1]
Lx_sup = distance.euclidean(vertices[0, :], vertices[1, :])
Ly_sup = distance.euclidean(vertices[0, :], vertices[3, :])
print("\tLattice constant (x) of moire cell: ", Lx_sup/10, "nm")
print("\tLattice constant (y) of moire cell: ", Ly_sup/10, "nm")
print()
return theta, N, Lx_sup, vertices
def create_layer2(layer1, m, r, H, v):
def rotate(layer, cos, sin):
layer_c = np.copy(layer)
layer[:, 1] = layer_c[:, 1] * cos - layer_c[:, 2] * sin
layer[:, 2] = layer_c[:, 1] * sin + layer_c[:, 2] * cos
return layer
layer2 = np.copy(layer1)
layer2[:, 3] += H
layer2[:, 0] += 1
c = (3 * m*m + 3*m*r + 0.5 * r*r)/ (3 * m*m + 3*m*r + r*r)
s = np.sqrt(1 - c*c)
layer2 = rotate(layer2, c, s)
ca = v[1, 0] - v[0, 0]
co = v[1, 1] - v[0, 1]
L = np.sqrt((co**2) + (ca**2))
cos = ca / L
sin = co / L
x1v = v[0, 0]
y1v = v[0, 1]
layer1[:, 1] -= x1v
layer1[:, 2] -= y1v
layer1 = rotate(layer1, cos, -sin)
layer2[:, 1] -= x1v
layer2[:, 2] -= y1v
layer2 = rotate(layer2, cos, -sin)
v[:, 0] -= x1v
v[:, 1] -= y1v
v_c = np.copy(v)
v[:, 0] = v_c[:, 0] * cos + v_c[:, 1] * sin
v[:, 1] = -v_c[:, 0] * sin + v_c[:, 1] * cos
unit = np.copy(v)
return layer1, layer2, v, unit
def plot_rotated_sys(layer1, layer2, bond, d_CC, N, count, vertices):
print("\tPlotting rotated layers ...")
C2 = layer2[0:N, 1:]
plt.scatter(C2[:, 0], C2[:, 1], marker='.', color='b')
C1 = layer1[0:N:3, 1:]
plt.scatter(C1[:, 0], C1[:, 1], marker='.', color='b')
plt.plot((layer2[bond[:count, 0], 1], layer2[bond[:count, 1], 1]), \
(layer2[bond[:count, 0], 2], layer2[bond[:count, 1], 2]), '-', color='blue')
plt.plot((layer1[bond[:count, 0], 1], layer1[bond[:count, 1], 1]), \
(layer1[bond[:count, 0], 2], layer1[bond[:count, 1], 2]), '-', color='red')
vertices_loc = np.copy(vertices)
dx = d_CC / 2
dy = d_CC / 2
vertices_loc[:, 0] += dx
vertices_loc[:, 1] -= dy
plt.plot(vertices_loc[:, 0], vertices_loc[:, 1], '-', color = 'cyan')
plt.plot(vertices[:, 0], vertices[:, 1], '-', color='black')
def cut_layer(nx, ny, d_CC, layer1, layer2, N, bond, count, vertices, unit):
dl = d_CC / 3
layer1[:, 1] += dl
layer1[:, 2] -= dl
layer2[:, 1] += dl
layer2[:, 2] -= dl
unit[:, 0] += dl
unit[:, 1] -= dl
L_sup = distance.euclidean(vertices[0, :], vertices[1, :])
Ly_sup = distance.euclidean(vertices[0, :], vertices[3, :])
m1 = (vertices[1, 1] - vertices[0, 1]) / (vertices[1, 0] - vertices[0, 0])
co = vertices[2, 1] - vertices[3, 1]
ca = vertices[2, 0] - vertices[3, 0]
m2 = co / ca
cos_phi = ca / np.sqrt(co**2 + ca**2)
sin_phi = co / np.sqrt(co**2 + ca**2)
co_v = vertices[2, 1] - vertices[1, 1]
ca_v = vertices[2, 0] - vertices[1, 0]
cos_theta = ca_v / np.sqrt(co_v**2 + ca_v**2)
sin_theta = co_v / np.sqrt(co_v**2 + ca_v**2)
sin_t_p = sin_theta*cos_phi - cos_theta*sin_phi
d = L_sup*sin_t_p
ly_v = d / cos_phi
def check_ver(xp, yp):
yl = vertices[0, 1] + m1 * (xp - vertices[0, 0])
yh = m1 * xp + (vertices[0, 1] - m1*vertices[0, 0] + ny*ly_v)
eps = 1e-6
if (yp - yl) >= eps and (yh - yp) >= eps :
return True
else:
return False
lx_h = d / sin_theta
ly_h = d / cos_theta
mi1 = (vertices[3, 0] - vertices[0, 0]) / (vertices[3, 1] - vertices[0, 1])
mi2 = (vertices[2, 0] - vertices[1, 0]) / (vertices[2, 1] - vertices[1, 1])
def check_hr(xp, yp):
xl = vertices[0, 0] + mi1 * (yp - vertices[0, 1])
xh = mi2 * yp + nx*lx_h
eps = 1e-6
if (xp - xl) >= eps and (xh - xp) >= eps:
return True
else:
return False
def bond_cut(layer, bond, count):
cut = np.zeros([N, 4], float)
cnt = 0
atom_list = np.zeros(N, int)
bond_l = np.zeros([count, 2], int)
b_c = 0
for b in range(count):
atom1 = False
atom2 = False
x1 = layer[bond[b, 0], 1]
x2 = layer[bond[b, 1], 1]
y1 = layer[bond[b, 0], 2]
y2 = layer[bond[b, 1], 2]
if check_ver(x1, y1) and check_hr(x1, y1):
if (bond[b, 0] in atom_list):
index_1, = np.where(atom_list == bond[b, 0])
index1 = index_1[0]
else:
atom_list[cnt] = bond[b, 0]
index1 = cnt
cut[cnt, :] = layer[bond[b, 0], :]
cnt += 1
atom1 = True
if check_ver(x2, y2) and check_hr(x2, y2):
if (bond[b, 1] in atom_list):
index_2, = np.where(atom_list == bond[b, 1])
index2 = index_2[0]
else:
atom_list[cnt] = bond[b, 1]
index2 = cnt
cut[cnt, :] = layer[bond[b, 1], :]
cnt += 1
atom2 = True
if atom1 and atom2:
bond_l[b_c, :] = [index1, index2]
b_c += 1
bond_l = bond_l[:b_c, :]
cut = cut[0:cnt, :]
return cut, cnt, bond_l, b_c
cut1, cnt1, bond1, b_c1 = bond_cut(layer1, bond, count)
cut2, cnt2, bond2, b_c2 = bond_cut(layer2, bond, count)
v_vecxh = vertices[1, 0] - vertices[0, 0]
v_vecyh = vertices[1, 1] - vertices[0, 1]
v_vecxv = vertices[3, 0] - vertices[0, 0]
v_vecyv = vertices[3, 1] - vertices[0, 1]
vertices[1:3, 0] += (nx-1)*v_vecxh
vertices[1:3, 1] += (nx-1)*v_vecyh
vertices[2:4, 0] += (ny-1)*v_vecxv
vertices[2:4, 1] += (ny-1)*v_vecyv
if (cnt1 != cnt2):
print(colored("\t[ERROR]:", 'red'), "No. of atoms in layer1 and layer2 does not matches")
print(colored("\t[SOLUTION]:", 'green'), "change the value of \"n_x\", \"n_y\", \"nx_ex\" and \"ny_ex\" \
inside the script (line no. 558 --> 561)")
print()
print("\tNumber of atoms in layer1 : ", cnt1)
print("\tNumber of atoms in layer2 : ", cnt2)
print("\tNumber of bonds in layer1 : ", b_c1)
print("\tNumber of bonds in layer2 : ", b_c2)
print()
Lx_sup = distance.euclidean(vertices[0, :], vertices[1, :])
Ly_sup = distance.euclidean(vertices[0, :], vertices[3, :])
print("\tTotal number of atoms in twisted system: ", (cnt1+cnt2))
print("\tTotal number of bonds in twisted system: ", (b_c1+b_c2))
print("\tLength of the twisted system: ", Lx_sup/10, "nm")
print("\tWidth of the twisted system: ", Ly_sup/10, "nm")
print()
return cut1, cnt1, cut2, cnt2, bond1, b_c1, bond2, b_c2, vertices, unit
def plot_twisted_system(layer1, cnt, layer2, cnt2, vertices, unit, bond1, b_c, bond2, b_c2):
print("\tPlotting twisted system ...")
fig, ax = plt.subplots()
S = 8.6
C_1 = layer1[:, 1:3]
C_2 = layer2[:, 1:3]
ax.scatter(C_1[:, 0], C_1[:, 1], s=S, marker='o',color='b')
ax.scatter(C_2[:, 0], C_2[:, 1], s=S, marker='o', color='r')
ax.plot(vertices[:, 0], vertices[:, 1], '-', color='black')
vecxh = unit[1, 0] - unit[0, 0]
vecyh = unit[1, 1] - unit[0, 1]
vecxv = unit[3, 0] - unit[0, 0]
vecyv = unit[3, 1] - unit[0, 1]
unit[:, 0] += (vecxh + vecxv)
unit[:, 1] += (vecyh + vecyv)
ax.plot(unit[:, 0], unit[:, 1], '-', color='blue')
ax.fill(unit[:4, 0], unit[:4, 1], 'c', alpha=0.4)
ax.plot((layer1[bond1[:b_c, 0], 1], layer1[bond1[:b_c, 1], 1]), \
(layer1[bond1[:b_c, 0], 2], layer1[bond1[:b_c, 1], 2]), '-', linewidth=0.82, color='black')
ax.plot((layer2[bond2[:b_c2, 0], 1], layer2[bond2[:b_c2, 1], 1]), \
(layer2[bond2[:b_c2, 0], 2], layer2[bond2[:b_c2, 1], 2]), '-', linewidth=0.82, color='black')
print()
# frame1 = plt.gca()
# frame1.axes.get_xaxis().set_visible(False)
# frame1.axes.get_yaxis().set_visible(False)
# plt.savefig('twisted_9.43.png', dpi=1200)
def write_data(theta, L_sup, Nx, Ny, H, v, Cz, \
layer1, cnt1, bond1, b_c1, layer2, cnt2, bond2, b_c2, bond_flag):
directory = "./LAMMPS_DATA_BOND/Angle_"+str("{:.1f}".format(theta))+"/"
filename = "data.Gr_"+str(int(L_sup*Nx/10))+"_"+str(int(L_sup*Ny/10))
file_path = os.path.join(directory, filename)
if not os.path.isdir(directory):
os.makedirs(directory)
layer = np.concatenate((layer1, layer2), axis=0)
N_tot = cnt1 + cnt2
f = open(file_path, "w+")
f.write("LAMMPS Atom File\n\n")
f.write("%d atoms\n" % N_tot)
if bond_flag:
f.write("%d bonds\n" % (b_c1+b_c2))
else:
f.write("0 bonds\n")
f.write("0 angles\n")
f.write("0 dihedrals\n")
f.write("0 impropers\n\n")
f.write("2 atom types\n")
if bond_flag:
f.write("1 bond types\n")
else:
f.write("0 bond types\n")
f.write("0 angle types\n\n")
f.write("%f %f xlo xhi\n" % (v[0, 0], v[1, 0]))
f.write("%f %f ylo yhi\n" % (v[0, 1], v[3, 1]))
f.write("%f %f zlo zhi\n" % ((Cz - 4*1.7), (Cz + H + 4*1.7)))
f.write("%f %f %f xy xz yz\n\n" % (v[3, 0], 0.00, 0.00))
f.write("Masses\n\n")
f.write(" 1 12.0107\n")
f.write(" 2 12.0107\n\n")
f.write("Atoms\n\n")
for k in range(N_tot):
mol_tag = 1
if k >= cnt1:
mol_tag = 2
f.write(" %d %d %d 0 %f %f %f\n"
% (k+1, mol_tag, layer[k, 0], layer[k, 1],
layer[k, 2], layer[k, 3]))
if bond_flag:
f.write("\n")
f.write("Bonds\n\n")
for b in range(b_c1):
f.write(" %d 1 %d %d\n" % (b+1, bond1[b, 0]+1, bond1[b, 1]+1))
bond2 += cnt1
for b2 in range(b_c2):
f.write(" %d 1 %d %d\n" % (b2+1+b_c1, bond2[b2, 0]+1, bond2[b2, 1]+1))
f.close()
print("\tLAMMPS data file '",filename,"' created in", directory)
print()
if __name__ == "__main__" :
d_CC = 1.42
Cz = 4*1.7
lx = d_CC * np.cos(np.pi/6) * 2
ly = 3 * d_CC
parser = argparse.ArgumentParser()
parser.add_argument("-Nx", type=int, default=4, help="Give integer value of Nx")
parser.add_argument("-Ny", type=int, default=4, help="Give integer value of Ny")
parser.add_argument("-H", type=float, default=3.412, help="Enter ILS in Anstrom")
parser.add_argument("-m", type=int, default=3, \
help="Enter integer value of m for the commensurate angle")
parser.add_argument("-r", type=int, default=1, \
help="Enter integer value of r for the commensurate angle")
parser.add_argument("--bond", dest='bond_flag', action='store_true', \
help="Enter boolean value of bond_flag")
parser.add_argument("--no-bond", dest='bond_flag', action='store_false', \
help="Enter boolean value of bond_flag")
parser.add_argument("--write", dest='write_flag', action='store_true', \
help="Enter boolean value to write data in LAMMPS input format")
parser.add_argument("--no-write", dest='write_flag', action='store_false', \
help="Enter boolean value to write data in LAMMPS input format")
parser.set_defaults(bond_flag=True, write_flag=True)
args = parser.parse_args()
Nx = args.Nx
Ny = args.Ny
H = args.H
m = args.m
r = args.r
bond_flag = args.bond_flag
write_flag = args.write_flag
theta, Num, L_sup, vertices = cs_theta(m, r, lx)
nx_ex = 14
ny_ex = 34
n_x = 24
n_y = 22
nx = nx_ex + (int(Nx*L_sup/lx) + 4) + n_x
ny = ny_ex + (int(Ny*L_sup/ly) + 4) + n_y
N_tot = ny*4*nx
layer1 = create_layer1(nx, ny, nx_ex, ny_ex, d_CC, Cz, lx, ly)
bond, count = create_bond(nx, ny)
layer1, layer2, vertices, unit = create_layer2(layer1, m, r, H, vertices)
#plot_rotated_sys(layer1, layer2, bond, d_MoS, N_tot, count, vertices)
layer1, cnt1, layer2, cnt2, bond1, b_c1 , bond2, b_c2, vertices, unit = \
cut_layer(Nx, Ny, d_CC, layer1, layer2, N_tot, bond, count, vertices, unit)
plot_twisted_system(layer1, cnt1, layer2, cnt2, vertices, unit, bond1, b_c1, bond2, b_c2)
if cnt1 == cnt2 and write_flag:
write_data(theta, L_sup, Nx, Ny, H, vertices, Cz, \
layer1, cnt1, bond1, b_c1, layer2, cnt2, bond2, b_c2, bond_flag)
plt.show()