-    WALSTROMITE     -    Ca2BaSi3O9

Theoretical atomic positions and lattice parameters at experimental volum from AMCSD 

Crystal Structure 


Because of the translational symmetry all the calculations are performed in the primitive unit cell and not in the conventional unit cell. The following information regarding the structure is given with respect to this primitive unit cell, which sometimes can take an unintuitive shape.

Symmetry (experimental): 

Space group:  P-1 
Lattice parameters (Å):  3.5630  5.0886  3.5577 
Angles (°):  69.6  102.3  96.9 

Symmetry (theoretical): 

Space group:  P-1 
Lattice parameters (Å):  6.6598  9.5265  6.6281 
Angles (°):  69.9  102.6  97.0 

Cell contents: 

Number of atoms:  30 
Number of atom types: 
Chemical composition: 

Atomic positions (theoretical):

Ca:  0.2693  0.5085  0.7589 
Ca:  0.4388  0.8272  0.9449 
Ba:  0.0495  0.8502  0.3203 
Si:  0.0947  0.2212  0.1508 
Si:  0.2321  0.4813  0.2843 
Si:  0.4404  0.1972  0.5138 
O:  0.2313  0.2593  0.9691 
O:  0.8984  0.1195  0.1004 
O:  0.0423  0.3707  0.1972 
O:  0.3733  0.5561  0.1074 
O:  0.1278  0.5858  0.3654 
O:  0.3569  0.3565  0.5074 
O:  0.6152  0.2363  0.3707 
O:  0.5088  0.0900  0.7557 
O:  0.2288  0.1244  0.3920 
Ca:  0.7307  0.4915  0.2411 
Ca:  0.5612  0.1728  0.0551 
Ba:  0.9505  0.1498  0.6797 
Si:  0.9053  0.7788  0.8492 
Si:  0.7679  0.5187  0.7157 
Si:  0.5596  0.8028  0.4862 
O:  0.7687  0.7407  0.0309 
O:  0.1016  0.8805  0.8996 
O:  0.9577  0.6293  0.8028 
O:  0.6267  0.4439  0.8926 
O:  0.8722  0.4142  0.6346 
O:  0.6431  0.6435  0.4926 
O:  0.3848  0.7637  0.6293 
O:  0.4912  0.9100  0.2443 
O:  0.7712  0.8756  0.6080 
Atom type 

We have listed here the reduced coordinates of all the atoms in the primitive unit cell.
It is enough to know only the position of the atoms from the assymetrical unit cell and then use the symmetry to build the whole crystal structure.

Visualization of the crystal structure: 

Size:

  
Nx:  Ny:  Nz:    
You can define the size of the supercell to be displayed in the jmol panel as integer translations along the three crys­tallo­gra­phic axis.
Please note that the structure is represented using the pri­mi­tive cell, and not the conventional one.
     

Powder Raman 

Powder Raman spectrum

The intensity of the Raman peaks is computed within the density-functional perturbation theory. The intensity depends on the temperature (for now fixed at 300K), frequency of the input laser (for now fixed at 21834 cm-1, frequency of the phonon mode and the Raman tensor. The Raman tensor represents the derivative of the dielectric tensor during the atomic displacement that corresponds to the phonon vibration. The Raman tensor is related to the polarizability of a specific phonon mode.

Horizontal:
Xmin:
Xmax:
Vertical:
Ymin:
Ymax:
 
Choose the polarization of the lasers.
I ∥ 
I ⊥ 
I Total 

Data about the phonon modes

Frequency of the transverse (TO) and longitudinal (LO) phonon modes in the zone-center. The longitudinal modes are computed along the three cartesian directions. You can visualize the atomic displacement pattern corresponding to each phonon by clicking on the appropriate cell in the table below.

1
ac
0
0
0
0
2
ac
0
0
0
0
3
ac
0
0
0
0
4
Ag
54
54
54
54
2.327e+39
4.5
1.927e+39
3.7
4.254e+39
8.1
5
Au
64
69
68
64
6
Au
85
90
86
86
7
Ag
90
90
90
90
4.169e+38
0.8
2.211e+38
0.4
6.380e+38
1.2
8
Ag
90
91
90
90
1.091e+39
2.1
2.267e+38
0.4
1.317e+39
2.5
9
Ag
103
103
103
103
1.112e+39
2.1
1.036e+39
2.0
2.147e+39
4.1
10
Au
111
112
111
115
11
Ag
115
115
115
115
1.636e+39
3.1
9.086e+38
1.7
2.544e+39
4.9
12
Ag
123
123
123
123
2.875e+39
5.5
3.526e+39
6.8
6.401e+39
12.3
13
Ag
137
137
137
137
14
Au
137
139
140
137
8.248e+38
1.6
4.779e+38
0.9
1.303e+39
2.5
15
Au
149
151
150
151
16
Ag
151
154
151
156
1.745e+39
3.3
1.305e+39
2.5
3.050e+39
5.8
17
Au
156
161
158
159
18
Ag
167
167
167
167
8.982e+38
1.7
5.942e+38
1.1
1.492e+39
2.9
19
Au
176
180
178
177
20
Ag
184
184
184
184
8.108e+38
1.6
1.086e+39
2.1
1.897e+39
3.6
21
Au
189
195
190
194
22
Au
195
201
201
195
23
Ag
201
208
201
201
9.191e+38
1.8
9.839e+38
1.9
1.903e+39
3.6
24
Ag
214
214
214
214
1.118e+39
2.1
3.533e+38
0.7
1.471e+39
2.8
25
Au
214
216
214
215
26
Au
216
223
223
218
27
Ag
223
225
233
223
4.864e+38
0.9
1.415e+38
0.3
6.278e+38
1.2
28
Au
236
236
238
247
29
Ag
247
247
247
252
1.073e+39
2.1
3.181e+38
0.6
1.392e+39
2.7
30
Ag
255
255
255
255
3.844e+38
0.7
3.891e+38
0.7
7.734e+38
1.5
31
Au
268
268
268
268
32
Au
273
274
274
274
33
Ag
274
274
276
276
1.433e+39
2.7
1.825e+39
3.5
3.259e+39
6.2
34
Ag
283
283
283
283
1.335e+39
2.6
1.230e+39
2.4
2.565e+39
4.9
35
Ag
288
288
288
288
2.158e+39
4.1
1.266e+39
2.4
3.424e+39
6.6
36
Au
295
297
296
298
37
Au
298
302
301
303
38
Ag
303
303
303
303
2.678e+39
5.1
2.396e+39
4.6
5.074e+39
9.7
39
Au
307
309
309
309
40
Ag
309
312
315
310
4.616e+38
0.9
5.035e+38
1.0
9.651e+38
1.8
41
Au
337
338
337
338
42
Ag
338
340
338
342
1.306e+39
2.5
8.501e+38
1.6
2.157e+39
4.1
43
Ag
349
349
349
349
7.410e+38
1.4
5.652e+38
1.1
1.306e+39
2.5
44
Au
350
360
350
358
45
Ag
360
362
360
360
6.369e+39
12.2
4.492e+39
8.6
1.086e+40
20.8
46
Au
363
365
364
368
47
Ag
384
384
384
384
4.797e+39
9.2
1.861e+39
3.6
6.659e+39
12.7
48
Au
393
393
393
393
49
Ag
397
397
397
397
2.544e+39
4.9
1.815e+39
3.5
4.358e+39
8.3
50
Au
401
402
402
402
51
Ag
428
428
428
428
52
Au
428
432
433
429
2.760e+39
5.3
3.030e+39
5.8
5.790e+39
11.1
53
Ag
441
441
441
441
9.786e+38
1.9
1.013e+39
1.9
1.991e+39
3.8
54
Au
452
453
452
453
55
Au
453
459
460
458
56
Ag
460
460
462
460
2.680e+39
5.1
1.687e+38
0.3
2.848e+39
5.5
57
Au
462
470
472
470
58
Ag
479
479
479
479
2.331e+39
4.5
1.374e+39
2.6
3.705e+39
7.1
59
Au
488
491
489
492
60
Ag
492
492
492
493
1.428e+39
2.7
8.774e+38
1.7
2.305e+39
4.4
61
Au
493
493
493
493
62
Ag
493
494
499
501
5.065e+39
9.7
9.000e+38
1.7
5.965e+39
11.4
63
Au
503
507
507
507
64
Ag
507
510
519
515
6.059e+38
1.2
6.545e+38
1.3
1.260e+39
2.4
65
Au
563
564
564
564
66
Ag
570
570
570
570
1.486e+39
2.8
1.254e+39
2.4
2.739e+39
5.2
67
Ag
638
638
638
638
5.206e+40
99.7
1.779e+38
0.3
5.223e+40
100.0
68
Au
643
644
643
648
69
Au
677
687
678
692
70
Au
706
710
710
706
71
Ag
710
711
724
710
3.177e+38
0.6
2.257e+38
0.4
5.434e+38
1.0
72
Ag
724
724
731
724
2.217e+38
0.4
9.656e+37
0.2
3.182e+38
0.6
73
Au
822
822
822
823
74
Ag
823
823
823
823
4.861e+38
0.9
2.909e+37
0.1
5.152e+38
1.0
75
Au
894
897
894
899
76
Ag
899
899
899
900
1.524e+39
2.9
5.002e+38
1.0
2.024e+39
3.9
77
Au
900
906
914
905
78
Ag
914
914
914
914
4.945e+39
9.5
2.911e+39
5.6
7.856e+39
15.0
79
Ag
922
922
922
922
1.031e+39
2.0
4.494e+38
0.9
1.480e+39
2.8
80
Au
931
939
931
937
81
Ag
939
940
939
939
5.696e+39
10.9
5.013e+38
1.0
6.197e+39
11.9
82
Au
949
952
973
949
83
Au
973
983
983
983
84
Ag
983
990
990
993
3.965e+40
75.9
4.726e+38
0.9
4.012e+40
76.8
85
Ag
1013
1013
1013
1013
8.862e+38
1.7
9.738e+37
0.2
9.835e+38
1.9
86
Au
1015
1016
1016
1024
87
Au
1024
1026
1040
1028
88
Ag
1040
1040
1044
1040
1.002e+40
19.2
2.590e+39
5.0
1.261e+40
24.1
89
Au
1045
1064
1059
1064
90
Ag
1064
1088
1064
1079
6.245e+39
12.0
3.170e+39
6.1
9.414e+39
18.0
No.  Char.  ω TO  ω LOx  ω LOy  ω LOz  I ∥  I ⊥  I Total 
You can define the size of the supercell for the visualization of the vibration.
Nx: 
Ny: 
Nz: 
Normalized
Raw
Options for intensity.