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
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
|
!
! Copyright (C) 2001-2011 Quantum ESPRESSO group
! This file is distributed under the terms of the
! GNU General Public License. See the file `License'
! in the root directory of the present distribution,
! or http://www.gnu.org/copyleft/gpl.txt .
!
!
!-------------------------------------------------------------------------
SUBROUTINE latgen_lib(ibrav,celldm,a1,a2,a3,omega, ierr, errormsg)
!-----------------------------------------------------------------------
! sets up the crystallographic vectors a1, a2, and a3.
!
! ibrav is the structure index:
! 1 cubic P (sc) 8 orthorhombic P
! 2 cubic F (fcc) 9 1-face (C) centered orthorhombic
! 3 cubic I (bcc) 10 all face centered orthorhombic
! 4 hexagonal and trigonal P 11 body centered orthorhombic
! 5 trigonal R, 3-fold axis c 12 monoclinic P (unique axis: c)
! 6 tetragonal P (st) 13 one face (base) centered monoclinic
! 7 tetragonal I (bct) 14 triclinic P
! Also accepted:
! 0 "free" structure -12 monoclinic P (unique axis: b)
! -3 cubic bcc with a more symmetric choice of axis
! -5 trigonal R, threefold axis along (111)
! -9 alternate description for base centered orthorhombic
! -13 one face (base) centered monoclinic (unique axis: b)
! 91 1-face (A) centered orthorombic
!
! celldm are parameters which fix the shape of the unit cell
! omega is the unit-cell volume
!
! NOTA BENE: all axis sets are right-handed
! Boxes for US PPs do not work properly with left-handed axis
!
USE kinds, ONLY: DP
IMPLICIT NONE
INTEGER, INTENT(in) :: ibrav
real(DP), INTENT(inout) :: celldm(6)
real(DP), INTENT(inout) :: a1(3), a2(3), a3(3)
real(DP), INTENT(out) :: omega
!
character(len=*),INTENT(out) :: errormsg
integer,INTENT(out) :: ierr
!
real(DP), PARAMETER:: sr2 = 1.414213562373d0, &
sr3 = 1.732050807569d0
INTEGER :: i,j,k,l,iperm,ir
real(DP) :: term, cbya, s, term1, term2, singam, sen
!
! pre-set to zero, in case we quit because of error
Omega = 0._dp
ierr = 0
errormsg = ''
!
! user-supplied lattice vectors
!
IF (ibrav == 0) THEN
IF (sqrt( a1(1)**2 + a1(2)**2 + a1(3)**2 ) == 0 ) &
THEN; errormsg='wrong at for ibrav=0'; ierr= 1; RETURN; ENDIF
IF (sqrt( a2(1)**2 + a2(2)**2 + a2(3)**2 ) == 0 ) &
THEN; errormsg='wrong at for ibrav=0'; ierr= 2; RETURN; ENDIF
IF (sqrt( a3(1)**2 + a3(2)**2 + a3(3)**2 ) == 0 ) &
THEN; errormsg='wrong at for ibrav=0'; ierr= 3; RETURN; ENDIF
IF ( celldm(1) /= 0.D0 ) THEN
!
! ... input at are in units of alat => convert them to a.u.
!
a1(:) = a1(:) * celldm(1)
a2(:) = a2(:) * celldm(1)
a3(:) = a3(:) * celldm(1)
ELSE
!
! ... input at are in atomic units: define celldm(1) from a1
!
celldm(1) = sqrt( a1(1)**2 + a1(2)**2 + a1(3)**2 )
ENDIF
!
ELSE
a1(:) = 0.d0
a2(:) = 0.d0
a3(:) = 0.d0
ENDIF
!
IF (celldm (1) <= 0.d0) THEN; errormsg='wrong celldm(1)'; ierr= abs(ibrav); RETURN; ENDIF
!
! index of bravais lattice supplied
!
IF (ibrav == 1) THEN
!
! simple cubic lattice
!
a1(1)=celldm(1)
a2(2)=celldm(1)
a3(3)=celldm(1)
!
ELSEIF (ibrav == 2) THEN
!
! fcc lattice
!
term=celldm(1)/2.d0
a1(1)=-term
a1(3)=term
a2(2)=term
a2(3)=term
a3(1)=-term
a3(2)=term
!
ELSEIF (abs(ibrav) == 3) THEN
!
! bcc lattice
!
term=celldm(1)/2.d0
DO ir=1,3
a1(ir)=term
a2(ir)=term
a3(ir)=term
ENDDO
IF ( ibrav < 0 ) THEN
a1(1)=-a1(1)
a2(2)=-a2(2)
a3(3)=-a3(3)
ELSE
a2(1)=-a2(1)
a3(1)=-a3(1)
a3(2)=-a3(2)
ENDIF
!
ELSEIF (ibrav == 4) THEN
!
! hexagonal lattice
!
IF (celldm (3) <= 0.d0) THEN; errormsg='wrong celldm(3)'; ierr= ibrav; RETURN; ENDIF
!
cbya=celldm(3)
a1(1)=celldm(1)
a2(1)=-celldm(1)/2.d0
a2(2)=celldm(1)*sr3/2.d0
a3(3)=celldm(1)*cbya
!
ELSEIF (abs(ibrav) == 5) THEN
!
! trigonal lattice
!
IF (celldm (4) <= -0.5_dp .or. celldm (4) >= 1.0_dp) &
THEN; errormsg='wrong celldm(4)'; ierr=5; RETURN; ENDIF
!
term1=sqrt(1.0_dp + 2.0_dp*celldm(4))
term2=sqrt(1.0_dp - celldm(4))
!
IF ( ibrav == 5) THEN
! threefold axis along c (001)
a2(2)=sr2*celldm(1)*term2/sr3
a2(3)=celldm(1)*term1/sr3
a1(1)=celldm(1)*term2/sr2
a1(2)=-a1(1)/sr3
a1(3)= a2(3)
a3(1)=-a1(1)
a3(2)= a1(2)
a3(3)= a2(3)
ELSEIF ( ibrav == -5) THEN
! threefold axis along (111)
! Notice that in the cubic limit (alpha=90, celldm(4)=0, term1=term2=1)
! does not yield the x,y,z axis, but an equivalent rotated triplet:
! a/3 (-1,2,2), a/3 (2,-1,2), a/3 (2,2,-1)
! If you prefer the x,y,z axis as cubic limit, you should modify the
! definitions of a1(1) and a1(2) as follows:'
! a1(1) = celldm(1)*(term1+2.0_dp*term2)/3.0_dp
! a1(2) = celldm(1)*(term1-term2)/3.0_dp
! (info by G. Pizzi and A. Cepellotti)
!
a1(1) = celldm(1)*(term1-2.0_dp*term2)/3.0_dp
a1(2) = celldm(1)*(term1+term2)/3.0_dp
a1(3) = a1(2)
a2(1) = a1(3)
a2(2) = a1(1)
a2(3) = a1(2)
a3(1) = a1(2)
a3(2) = a1(3)
a3(3) = a1(1)
ENDIF
ELSEIF (ibrav == 6) THEN
!
! tetragonal lattice
!
IF (celldm (3) <= 0.d0) THEN; errormsg='wrong celldm(3)'; ierr=6; RETURN; ENDIF
!
cbya=celldm(3)
a1(1)=celldm(1)
a2(2)=celldm(1)
a3(3)=celldm(1)*cbya
!
ELSEIF (ibrav == 7) THEN
!
! body centered tetragonal lattice
!
IF (celldm (3) <= 0.d0) THEN; errormsg='wrong celldm(3)'; ierr=7; RETURN; ENDIF
!
cbya=celldm(3)
a2(1)=celldm(1)/2.d0
a2(2)=a2(1)
a2(3)=cbya*celldm(1)/2.d0
a1(1)= a2(1)
a1(2)=-a2(1)
a1(3)= a2(3)
a3(1)=-a2(1)
a3(2)=-a2(1)
a3(3)= a2(3)
!
ELSEIF (ibrav == 8) THEN
!
! Simple orthorhombic lattice
!
IF (celldm (2) <= 0.d0) THEN; errormsg='wrong celldm(2)'; ierr=8; RETURN; ENDIF
IF (celldm (3) <= 0.d0) THEN; errormsg='wrong celldm(3)'; ierr=8; RETURN; ENDIF
!
a1(1)=celldm(1)
a2(2)=celldm(1)*celldm(2)
a3(3)=celldm(1)*celldm(3)
!
ELSEIF ( abs(ibrav) == 9) THEN
!
! One face (base) centered orthorhombic lattice (C type)
!
IF (celldm (2) <= 0.d0) THEN; errormsg='wrong celldm(2)'; ierr=9; RETURN; ENDIF
IF (celldm (3) <= 0.d0) THEN; errormsg='wrong celldm(3)'; ierr=9; RETURN; ENDIF
!
IF ( ibrav == 9 ) THEN
! old PWscf description
a1(1) = 0.5d0 * celldm(1)
a1(2) = a1(1) * celldm(2)
a2(1) = - a1(1)
a2(2) = a1(2)
ELSE
! alternate description
a1(1) = 0.5d0 * celldm(1)
a1(2) =-a1(1) * celldm(2)
a2(1) = a1(1)
a2(2) =-a1(2)
ENDIF
a3(3) = celldm(1) * celldm(3)
!
ELSEIF ( ibrav == 91 ) THEN
!
! One face (base) centered orthorhombic lattice (A type)
!
IF (celldm (2) <= 0.d0) THEN; errormsg='wrong celldm(2)'; ierr=91; RETURN; ENDIF
IF (celldm (3) <= 0.d0) THEN; errormsg='wrong celldm(3)'; ierr=91; RETURN; ENDIF
!
a1(1) = celldm(1)
a2(2) = celldm(1) * celldm(2) * 0.5_DP
a2(3) = - celldm(1) * celldm(3) * 0.5_DP
a3(2) = a2(2)
a3(3) = - a2(3)
!
ELSEIF (ibrav == 10) THEN
!
! All face centered orthorhombic lattice
!
IF (celldm (2) <= 0.d0) THEN; errormsg='wrong celldm(2)'; ierr=10; RETURN; ENDIF
IF (celldm (3) <= 0.d0) THEN; errormsg='wrong celldm(3)'; ierr=10; RETURN; ENDIF
!
a2(1) = 0.5d0 * celldm(1)
a2(2) = a2(1) * celldm(2)
a1(1) = a2(1)
a1(3) = a2(1) * celldm(3)
a3(2) = a2(1) * celldm(2)
a3(3) = a1(3)
!
ELSEIF (ibrav == 11) THEN
!
! Body centered orthorhombic lattice
!
IF (celldm (2) <= 0.d0) THEN; errormsg='wrong celldm(2)'; ierr=11; RETURN; ENDIF
IF (celldm (3) <= 0.d0) THEN; errormsg='wrong celldm(3)'; ierr=11; RETURN; ENDIF
!
a1(1) = 0.5d0 * celldm(1)
a1(2) = a1(1) * celldm(2)
a1(3) = a1(1) * celldm(3)
a2(1) = - a1(1)
a2(2) = a1(2)
a2(3) = a1(3)
a3(1) = - a1(1)
a3(2) = - a1(2)
a3(3) = a1(3)
!
ELSEIF (ibrav == 12) THEN
!
! Simple monoclinic lattice, unique (i.e. orthogonal to a) axis: c
!
IF (celldm (2) <= 0.d0) THEN; errormsg='wrong celldm(2)'; ierr=12; RETURN; ENDIF
IF (celldm (3) <= 0.d0) THEN; errormsg='wrong celldm(3)'; ierr=12; RETURN; ENDIF
IF (abs(celldm(4))>=1.d0) THEN; errormsg='wrong celldm(4)'; ierr=12; RETURN; ENDIF
!
sen=sqrt(1.d0-celldm(4)**2)
a1(1)=celldm(1)
a2(1)=celldm(1)*celldm(2)*celldm(4)
a2(2)=celldm(1)*celldm(2)*sen
a3(3)=celldm(1)*celldm(3)
!
ELSEIF (ibrav ==-12) THEN
!
! Simple monoclinic lattice, unique axis: b (more common)
!
IF (celldm (2) <= 0.d0) THEN; errormsg='wrong celldm(2)'; ierr=12; RETURN; ENDIF
IF (celldm (3) <= 0.d0) THEN; errormsg='wrong celldm(3)'; ierr=12; RETURN; ENDIF
IF (abs(celldm(5))>=1.d0) THEN; errormsg='wrong celldm(5)'; ierr=12; RETURN; ENDIF
!
sen=sqrt(1.d0-celldm(5)**2)
a1(1)=celldm(1)
a2(2)=celldm(1)*celldm(2)
a3(1)=celldm(1)*celldm(3)*celldm(5)
a3(3)=celldm(1)*celldm(3)*sen
!
ELSEIF (ibrav == 13) THEN
!
! One face centered monoclinic lattice unique axis c
!
IF (celldm (2) <= 0.d0) THEN; errormsg='wrong celldm(2)'; ierr=13; RETURN; ENDIF
IF (celldm (3) <= 0.d0) THEN; errormsg='wrong celldm(3)'; ierr=13; RETURN; ENDIF
IF (abs(celldm(4))>=1.d0) THEN; errormsg='wrong celldm(4)'; ierr=13; RETURN; ENDIF
!
sen = sqrt( 1.d0 - celldm(4) ** 2 )
a1(1) = 0.5d0 * celldm(1)
a1(3) =-a1(1) * celldm(3)
a2(1) = celldm(1) * celldm(2) * celldm(4)
a2(2) = celldm(1) * celldm(2) * sen
a3(1) = a1(1)
a3(3) =-a1(3)
ELSEIF (ibrav == -13) THEN
errormsg='BEWARE: axis for ibrav=-13 changed, see documentation!'
!
! One face centered monoclinic lattice unique axis b
!
IF (celldm (2) <= 0.d0) THEN; errormsg='wrong celldm(2)'; ierr=13; RETURN; ENDIF
IF (celldm (3) <= 0.d0) THEN; errormsg='wrong celldm(3)'; ierr=13; RETURN; ENDIF
IF (abs(celldm(5))>=1.d0) THEN; errormsg='wrong celldm(5)'; ierr=13; RETURN; ENDIF
!
sen = sqrt( 1.d0 - celldm(5) ** 2 )
a1(1) = 0.5d0 * celldm(1)
a1(2) = a1(1) * celldm(2)
a2(1) =-a1(1)
a2(2) = a1(2)
a3(1) = celldm(1) * celldm(3) * celldm(5)
a3(3) = celldm(1) * celldm(3) * sen
!
ELSEIF (ibrav == 14) THEN
!
! Triclinic lattice
!
IF (celldm (2) <= 0.d0) THEN; errormsg='wrong celldm(2)'; ierr=14; RETURN; ENDIF
IF (celldm (3) <= 0.d0) THEN; errormsg='wrong celldm(3)'; ierr=14; RETURN; ENDIF
IF (abs(celldm(4))>=1.d0) THEN; errormsg='wrong celldm(4)'; ierr=14; RETURN; ENDIF
IF (abs(celldm(5))>=1.d0) THEN; errormsg='wrong celldm(5)'; ierr=14; RETURN; ENDIF
IF (abs(celldm(6))>=1.d0) THEN; errormsg='wrong celldm(6)'; ierr=14; RETURN; ENDIF
!
singam=sqrt(1.d0-celldm(6)**2)
term= (1.d0+2.d0*celldm(4)*celldm(5)*celldm(6) &
-celldm(4)**2-celldm(5)**2-celldm(6)**2)
IF (term < 0.d0) THEN; errormsg='celldm do not make sense, check your data'; ierr=14; RETURN; ENDIF
term= sqrt(term/(1.d0-celldm(6)**2))
a1(1)=celldm(1)
a2(1)=celldm(1)*celldm(2)*celldm(6)
a2(2)=celldm(1)*celldm(2)*singam
a3(1)=celldm(1)*celldm(3)*celldm(5)
a3(2)=celldm(1)*celldm(3)*(celldm(4)-celldm(5)*celldm(6))/singam
a3(3)=celldm(1)*celldm(3)*term
!
ELSE IF (ibrav /= 0) THEN
!
errormsg='nonexistent bravais lattice'
ierr=ABS(ibrav)
RETURN
!
ENDIF
!
! calculate unit-cell volume omega
!
CALL volume (1.0_dp, a1, a2, a3, omega)
!
RETURN
!
END SUBROUTINE latgen_lib
!
!-------------------------------------------------------------------------
SUBROUTINE at2celldm (ibrav,alat,a1,a2,a3,celldm)
!-----------------------------------------------------------------------
!
! Returns celldm parameters computed from lattice vectors a1,a2,a3
! a1, a2, a3 are in "alat" units
! If Bravais lattice index ibrav=0, only celldm(1) is set to alat
! See latgen for definition of celldm and lattice vectors.
! a1, a2, a3, ibrav, alat are not modified
!
USE kinds, ONLY: DP
IMPLICIT NONE
INTEGER, INTENT(in) :: ibrav
REAL(DP), INTENT(in) :: alat, a1(3), a2(3), a3(3)
REAL(DP), INTENT(out) :: celldm(6)
!
celldm = 0.d0
!
SELECT CASE ( ibrav )
CASE (0)
celldm(1) = 1.0_dp
CASE (1)
celldm(1) = sqrt( dot_product (a1,a1) )
CASE (2)
celldm(1) = sqrt( dot_product (a1,a1) * 2.0_dp )
CASE (3,-3)
celldm(1) = sqrt( dot_product (a1,a1) / 3.0_dp ) * 2.0_dp
CASE (4)
celldm(1) = sqrt( dot_product (a1,a1) )
celldm(3) = sqrt( dot_product (a3,a3) ) / celldm(1)
CASE (5, -5 )
celldm(1) = sqrt( dot_product (a1,a1) )
celldm(4) = dot_product(a1(:),a2(:)) / celldm(1) &
/ sqrt( dot_product( a2,a2) )
CASE (6)
celldm(1)= sqrt( dot_product (a1,a1) )
celldm(3)= sqrt( dot_product (a3,a3) ) / celldm(1)
CASE (7)
celldm(1) = abs(a1(1))*2.0_dp
celldm(3) = abs(a1(3)/a1(1))
CASE (8)
celldm(1) = sqrt( dot_product (a1,a1) )
celldm(2) = sqrt( dot_product (a2,a2) ) / celldm(1)
celldm(3) = sqrt( dot_product (a3,a3) ) / celldm(1)
CASE (9, -9 )
celldm(1) = abs(a1(1))*2.0_dp
celldm(2) = abs(a2(2))*2.0_dp/celldm(1)
celldm(3) = abs(a3(3))/celldm(1)
CASE (91 )
celldm(1) = sqrt( dot_product (a1,a1) )
celldm(2) = abs (a2(2))*2.0_dp/celldm(1)
celldm(3) = abs (a3(3))*2.0_dp/celldm(1)
CASE (10)
celldm(1) = abs(a1(1))*2.0_dp
celldm(2) = abs(a2(2))*2.0_dp/celldm(1)
celldm(3) = abs(a3(3))*2.0_dp/celldm(1)
CASE (11)
celldm(1) = abs(a1(1))*2.0_dp
celldm(2) = abs(a1(2))*2.0_dp/celldm(1)
celldm(3) = abs(a1(3))*2.0_dp/celldm(1)
CASE (12,-12)
celldm(1) = sqrt( dot_product (a1,a1) )
celldm(2) = sqrt( dot_product(a2(:),a2(:)) ) / celldm(1)
celldm(3) = sqrt( dot_product(a3(:),a3(:)) ) / celldm(1)
IF ( ibrav == 12 ) THEN
celldm(4) = dot_product(a1(:),a2(:)) / celldm(1) / &
sqrt(dot_product(a2(:),a2(:)))
ELSE
celldm(5) = dot_product(a1(:),a3(:)) / celldm(1) / &
sqrt(dot_product(a3(:),a3(:)))
ENDIF
CASE (13)
celldm(1) = abs(a1(1))*2.0_dp
celldm(2) = sqrt( dot_product(a2(:),a2(:))) / celldm(1)
celldm(3) = abs (a1(3)/a1(1))
celldm(4) = a2(1)/a1(1)/celldm(2)/2.0_dp
! SQRT(DOT_PRODUCT(a1(:),a1(:)) * DOT_PRODUCT(a2(:),a2(:)))
!celldm(4) = DOT_PRODUCT(a1(:),a2(:)) / &
! SQRT(DOT_PRODUCT(a1(:),a1(:)) * DOT_PRODUCT(a2(:),a2(:)))
CASE (-13)
celldm(1) = abs(a1(1))*2.0_dp
celldm(2) = abs (a2(2)/a2(1))
celldm(3) = sqrt( dot_product(a3(:),a3(:))) / celldm(1)
celldm(5) = a3(1)/a1(1)/celldm(3)/2.0_dp
!celldm(5) = DOT_PRODUCT(a1(:),a3(:)) / &
! SQRT(DOT_PRODUCT(a1(:),a1(:)) * DOT_PRODUCT(a3(:),a3(:)))
CASE (14)
celldm(1) = sqrt(dot_product(a1(:),a1(:)))
celldm(2) = sqrt( dot_product(a2(:),a2(:))) / celldm(1)
celldm(3) = sqrt( dot_product(a3(:),a3(:))) / celldm(1)
celldm(4) = dot_product(a3(:),a2(:))/sqrt(dot_product(a2(:),a2(:)) * &
dot_product(a3(:),a3(:)))
celldm(5) = dot_product(a3(:),a1(:)) / celldm(1) / &
sqrt( dot_product(a3(:),a3(:)))
celldm(6) = dot_product(a1(:),a2(:)) / celldm(1) / &
sqrt(dot_product(a2(:),a2(:)))
CASE DEFAULT
CALL infomsg('at2celldm', 'wrong ibrav?')
END SELECT
!
celldm(1) = celldm(1) * alat
!
END SUBROUTINE at2celldm
!
FUNCTION at2ibrav (a1, a2, a3) RESULT (ibrav)
!
! Returns ibrav from lattice vectors if recognized, 0 otherwise
!
USE kinds, ONLY: dp
IMPLICIT NONE
REAL(dp), INTENT (in) :: a1(3), a2(3), a3(3)
REAL(dp) :: v1, v2, v3, cosab, cosac, cosbc
!
INTEGER :: ibrav
!
v1 = sqrt( dot_product( a1,a1 ) )
v2 = sqrt( dot_product( a2,a2 ) )
v3 = sqrt( dot_product( a3,a3 ) )
cosbc = dot_product(a2,a3)/v2/v3
cosac = dot_product(a1,a3)/v1/v3
cosab = dot_product(a1,a2)/v1/v2
!
! Assume triclinic if nothing suitable found
!
ibrav = 14
IF ( eqq(v1,v2) .and. eqq(v1,v3) ) THEN
! Case: a=b=c
IF (eqq(cosab,cosac) .and. eqq(cosab,cosbc)) THEN
! Case: alpha = beta = gamma
IF ( eqq(cosab,0.0_dp) ) THEN
! Cubic P - ibrav=1
ibrav = 1
ELSEIF ( eqq(cosab,0.5_dp) ) THEN
! Cubic F - ibrav=2
ibrav = 2
ELSEIF ( eqq(cosab,-1.0_dp/3.0_dp) ) THEN
! Cubic I - ibrav=-3
ibrav = -3
ELSE
IF ( eqq(abs(a1(3)),abs(a2(3))) .and. eqq(abs(a2(3)),abs(a3(3))) ) THEN
! Trigonal 001 axis
ibrav =5
ELSE
! Trigonal, 111 axis
ibrav =-5
ENDIF
!
ENDIF
!
ELSEIF ( eqq(cosab,cosac) .and. neqq(cosab,cosbc) ) THEN
IF ( eqq(abs(a1(1)),abs(a1(2))) .and. &
eqq(abs(a2(1)),abs(a2(2))) ) THEN
! Tetragonal I
ibrav = 7
ELSE
! Cubic I - ibrav=3
ibrav = 3
ENDIF
ELSEIF ( eqq(cosab,-cosac) .and. eqq(cosab,cosbc) .and. &
eqq(cosab,1.0_dp/3.0_dp) ) THEN
! Cubic I - ibrav=3
ibrav = 3
ELSEIF ( eqq(abs(a1(1)),abs(a2(1))) .and. &
eqq(abs(a2(2)),abs(a2(2))) ) THEN
! Orthorhombic body-centered
ibrav = 11
ENDIF
!
ELSEIF ( eqq(v1,v2) .and. neqq(v1,v3) ) THEN
! Case: a=b/=c
IF ( eqq(cosab,0.0_dp) .and. eqq(cosac,0.0_dp) .and. eqq(cosbc,0.0_dp) ) THEN
! Case: alpha = beta = gamma = 90
! Simple tetragonal
ibrav = 6
ELSEIF ( eqq(cosab,-0.5_dp) .and. eqq(cosac,0.0_dp) .and. eqq(cosbc,0.0_dp) ) THEN
! Case: alpha = 120, beta = gamma = 90 => simple hexagonal
! Simple hexagonal
ibrav = 4
ELSEIF ( eqq(cosac,0.0_dp) .and. eqq(cosbc,0.0_dp) ) THEN
! Orthorhombic bco
IF ( eqq(a1(1),a2(1)) .and. eqq(a1(2),-a2(2))) THEN
ibrav = -9
ELSEIF ( eqq(a1(1),-a2(1)) .and. eqq(a1(2),a2(2))) THEN
ibrav = 9
ENDIF
ELSEIF ( eqq(cosac,-cosbc) ) THEN
! bco (unique axis b)
ibrav =-13
ENDIF
ELSEIF ( eqq(v1,v3) .and. neqq(v1,v2) ) THEN
! Case: a=c/=b
! Monoclinic bco (unique axis c)
ibrav = 13
!
ELSEIF ( eqq(v2,v3) .and. neqq(v1,v2) ) THEN
! Case: a/=b=c
! Orthorhombic 1-face bco
ibrav = 91
!
ELSEIF ( neqq(v1,v2) .and. neqq(v1,v3) .and. neqq(v2,v3) ) THEN
! Case: a/=b/=c
IF ( eqq(cosab,0.0_dp) .and. eqq(cosac,0.0_dp) .and. eqq(cosbc,0.0_dp) ) THEN
! Case: alpha = beta = gamma = 90
! Orthorhombic P
ibrav = 8
ELSEIF ( neqq(cosab,0.0_dp) .and. eqq(cosac,0.0_dp) .and. eqq(cosbc,0.0_dp) ) THEN
! Case: alpha /= 90, beta = gamma = 90
! Monoclinic P, unique axis c
ibrav = 12
ELSEIF ( eqq(cosab,0.0_dp) .and. neqq(cosac,0.0_dp) .and. eqq(cosbc,0.0_dp) ) THEN
! Case: beta /= 90, alpha = gamma = 90
! Monoclinic P, unique axis b
ibrav =-12
ELSEIF ( neqq(cosab,0.0_dp) .and. neqq(cosac,0.0_dp) .and. neqq(cosbc,0.0_dp) ) THEN
! Case: alpha /= 90, beta /= 90, gamma /= 90
IF ( eqq(abs(a1(1)),abs(a2(1))) .and. eqq(abs(a1(3)),abs(a3(3))) .and. &
eqq(abs(a2(2)),abs(a3(2))) ) THEN
! Orthorhombic F
ibrav = 10
ELSE
! Triclinic
ibrav = 14
ENDIF
ENDIF
!
ENDIF
!
CONTAINS
!
LOGICAL FUNCTION eqq (x,y)
REAL(dp), INTENT (in) :: x,y
eqq = abs(x-y) < 1.0d-5
END FUNCTION eqq
LOGICAL FUNCTION neqq (x,y)
REAL(dp), INTENT (in) :: x,y
neqq= abs(x-y) > 1.0d-5
END FUNCTION neqq
!
END FUNCTION at2ibrav
!
SUBROUTINE abc2celldm ( ibrav, a,b,c,cosab,cosac,cosbc, celldm )
!
! returns internal parameters celldm from crystallographics ones
!
USE kinds, ONLY: dp
USE constants, ONLY: bohr_radius_angs
IMPLICIT NONE
!
INTEGER, INTENT (in) :: ibrav
REAL(DP), INTENT (in) :: a,b,c, cosab, cosac, cosbc
REAL(DP), INTENT (out) :: celldm(6)
!
IF (a <= 0.0_dp) CALL errore('abc2celldm','incorrect lattice parameter (a)',1)
IF (b < 0.0_dp) CALL errore('abc2celldm','incorrect lattice parameter (b)',1)
IF (c < 0.0_dp) CALL errore('abc2celldm','incorrect lattice parameter (c)',1)
IF ( abs (cosab) > 1.0_dp) CALL errore('abc2celldm', &
'incorrect lattice parameter (cosab)',1)
IF ( abs (cosac) > 1.0_dp) CALL errore('abc2celldm', &
'incorrect lattice parameter (cosac)',1)
IF ( abs (cosbc) > 1.0_dp) CALL errore('abc2celldm', &
'incorrect lattice parameter (cosbc)',1)
!
celldm(1) = a / bohr_radius_angs
celldm(2) = b / a
celldm(3) = c / a
!
IF ( ibrav == 14 .or. ibrav == 0 ) THEN
!
! ... triclinic lattice
!
celldm(4) = cosbc
celldm(5) = cosac
celldm(6) = cosab
!
ELSEIF ( ibrav ==-12 .or. ibrav ==-13 ) THEN
!
! ... monoclinic P or base centered lattice, unique axis b
!
celldm(4) = 0.0_dp
celldm(5) = cosac
celldm(6) = 0.0_dp
!
ELSEIF ( ibrav ==-5 .or. ibrav ==5 .or. ibrav ==12 .or. ibrav ==13 ) THEN
!
! ... trigonal and monoclinic lattices, unique axis c
!
celldm(4) = cosab
celldm(5) = 0.0_dp
celldm(6) = 0.0_dp
!
ELSE
!
celldm(4) = 0.0_dp
celldm(5) = 0.0_dp
celldm(6) = 0.0_dp
!
ENDIF
!
END SUBROUTINE abc2celldm
!
SUBROUTINE celldm2abc ( ibrav, celldm, a,b,c,cosab,cosac,cosbc )
!
! returns crystallographic parameters a,b,c from celldm
!
USE kinds, ONLY: dp
USE constants, ONLY: bohr_radius_angs
IMPLICIT NONE
!
INTEGER, INTENT (in) :: ibrav
REAL(DP), INTENT (in) :: celldm(6)
REAL(DP), INTENT (out) :: a,b,c, cosab, cosac, cosbc
!
!
a = celldm(1) * bohr_radius_angs
b = celldm(1)*celldm(2) * bohr_radius_angs
c = celldm(1)*celldm(3) * bohr_radius_angs
!
IF ( ibrav == 14 .or. ibrav == 0 ) THEN
!
! ... triclinic lattice
!
cosbc = celldm(4)
cosac = celldm(5)
cosab = celldm(6)
!
ELSEIF ( ibrav ==-12 .or. ibrav ==-13 ) THEN
!
! ... monoclinic P or base centered lattice, unique axis b
!
cosab = 0.0_dp
cosac = celldm(5)
cosbc = 0.0_dp
!
ELSEIF ( ibrav ==-5 .or. ibrav ==5 .or. ibrav ==12 .or. ibrav ==13 ) THEN
!
! ... trigonal and monoclinic lattices, unique axis c
!
cosab = celldm(4)
cosac = 0.0_dp
cosbc = 0.0_dp
!
ELSE
cosab = 0.0_dp
cosac = 0.0_dp
cosbc = 0.0_dp
ENDIF
!
END SUBROUTINE celldm2abc
SUBROUTINE remake_cell(ibrav, alat, a1,a2,a3)
USE kinds, ONLY : DP
USE io_global, ONLY : stdout
IMPLICIT NONE
INTEGER,INTENT(in) :: ibrav
REAL(DP),INTENT(inout) :: alat, a1(3),a2(3),a3(3)
REAL(DP) :: e1(3), e2(3), e3(3)
REAL(DP) :: celldm_internal(6), lat_internal, omega
! Better not to do the following, or it may cause problems with ibrav=0 from input
! ibrav = at2ibrav (a(:,1), a(:,2), a(:,3))
! Instead, let's print a warning and do nothing:
IF(ibrav==0)THEN
WRITE(stdout,'(a)') "WARNING! With ibrav=0, cell_dofree='ibrav' does not have any effect. "
RETURN
ENDIF
!
CALL at2celldm (ibrav,alat,a1, a2, a3,celldm_internal)
WRITE(stdout,'("ibrav = ",i6)') ibrav
WRITE(stdout,'(" celldm(1) = ",f15.8)') celldm_internal(1)
IF( celldm_internal(2) /= 0._dp) WRITE(stdout,'(" celldm(2) = ",f15.8)') celldm_internal(2)
IF( celldm_internal(3) /= 0._dp) WRITE(stdout,'(" celldm(3) = ",f15.8)') celldm_internal(3)
IF( celldm_internal(4) /= 0._dp) WRITE(stdout,'(" celldm(4) = ",f15.8)') celldm_internal(4)
IF( celldm_internal(5) /= 0._dp) WRITE(stdout,'(" celldm(5) = ",f15.8)') celldm_internal(5)
IF( celldm_internal(6) /= 0._dp) WRITE(stdout,'(" celldm(6) = ",f15.8)') celldm_internal(6)
!
e1=a1
e2=a2
e3=a3
CALL latgen( ibrav, celldm_internal, a1,a2,a3, omega )
!WRITE(*, '("New lattice vectors in bohr:")')
!WRITE(*,'(3f15.8)') e(:,1)
!WRITE(*,'(3f15.8)') e(:,2)
!WRITE(*,'(3f15.8)') e(:,3)
WRITE(stdout,'("Input lattice vectors:")')
WRITE(stdout,'(3f15.8)') e1
WRITE(stdout,'(3f15.8)') e2
WRITE(stdout,'(3f15.8)') e3
WRITE(stdout,'("New lattice vectors in INITIAL alat:")')
WRITE(stdout,'(3f15.8)') a1/alat
WRITE(stdout,'(3f15.8)') a2/alat
WRITE(stdout,'(3f15.8)') a3/alat
WRITE(stdout, '("New lattice vectors in NEW alat (for information only):")')
WRITE(stdout,'(3f15.8)') a1/celldm_internal(1)
WRITE(stdout,'(3f15.8)') a2/celldm_internal(1)
WRITE(stdout,'(3f15.8)') a3/celldm_internal(1)
a1=a1/alat
a2=a2/alat
a3=a3/alat
WRITE(*,'("Discrepancy in bohr = ", 3f12.6)') DSQRT(SUM((a1-e1)**2)), DSQRT(SUM((a2-e2)**2)), DSQRT(SUM((a3-e3)**2))
END SUBROUTINE
!-------------------------------------------------------------------------
SUBROUTINE latgen(ibrav,celldm,a1,a2,a3,omega)
!-----------------------------------------------------------------------
USE kinds, ONLY: DP
IMPLICIT NONE
INTEGER, INTENT(in) :: ibrav
real(DP), INTENT(inout) :: celldm(6)
real(DP), INTENT(inout) :: a1(3), a2(3), a3(3)
real(DP), INTENT(out) :: omega
!
character(len=54) :: errormsg
integer :: ierr
CALL latgen_lib(ibrav,celldm,a1,a2,a3,omega, ierr, errormsg)
IF(ierr /= 0 ) THEN
CALL errore("latgen", errormsg, abs(ierr))
ELSE
IF(errormsg/='') CALL infomsg('latgen',errormsg)
ENDIF
!
END SUBROUTINE
|
