-    LARNITE     -    Ca2SiO4

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:  14  P2_1/c 
Lattice parameters (Å):  5.5041  6.7622  9.3281 
Angles (°):  90.0  94.2  90.0 

Symmetry (theoretical): 

Space group:  14  P2_1/c 
Lattice parameters (Å):  5.5185  6.7781  9.2992 
Angles (°):  90.0  95.3  90.0 

Cell contents: 

Number of atoms:  28 
Number of atom types:  3 
Chemical composition:  0 

Atomic positions (theoretical):

Ca:  0.2248  0.3457  0.4322 
Ca:  0.2141  0.9992  0.7001 
Si:  0.2672  0.7802  0.4182 
O:  0.2117  0.0089  0.4392 
O:  0.0149  0.6652  0.3623 
O:  0.4777  0.7495  0.3096 
O:  0.3465  0.6710  0.5726 
Ca:  0.2752  0.8457  0.0678 
Ca:  0.2859  0.4992  0.7999 
Si:  0.2328  0.2802  0.0818 
O:  0.2883  0.5089  0.0608 
O:  0.4851  0.1652  0.1377 
O:  0.0223  0.2495  0.1904 
O:  0.1535  0.1710  0.9274 
Ca:  0.7752  0.6543  0.5678 
Ca:  0.7859  0.0008  0.2999 
Si:  0.7328  0.2198  0.5818 
O:  0.7883  0.9911  0.5608 
O:  0.9851  0.3348  0.6377 
O:  0.5223  0.2505  0.6904 
O:  0.6535  0.3290  0.4274 
Ca:  0.7248  0.1543  0.9322 
Ca:  0.7141  0.5008  0.2001 
Si:  0.7672  0.7198  0.9182 
O:  0.7117  0.4911  0.9392 
O:  0.5149  0.8348  0.8623 
O:  0.9777  0.7505  0.8096 
O:  0.8465  0.8290  0.0726 
Atom type  X  Y  Z 

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.

Choose the polarization of the lasers.

I ∥ 
I ⊥ 
I Total 
Horizontal:
Xmin:
Xmax:
Vertical:
Ymin:
Ymax:
 

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
Bg
99
99
99
99
2.292e+38
0.5
3.737e+38
0.8
6.030e+38
1.3
5
Au
112
112
112
112
6
Bu
113
113
113
113
7
Ag
118
118
118
118
9.267e+37
0.2
6.748e+37
0.1
1.601e+38
0.3
8
Au
130
130
133
130
9
Ag
143
143
143
143
3.576e+38
0.8
2.439e+38
0.5
6.016e+38
1.3
10
Ag
150
150
150
150
1.426e+39
3.0
5.262e+38
1.1
1.952e+39
4.2
11
Au
150
150
151
150
12
Bg
151
151
158
151
1.098e+38
0.2
1.771e+38
0.4
2.869e+38
0.6
13
Bu
163
164
163
163
14
Ag
169
169
169
169
1.402e+39
3.0
1.050e+39
2.2
2.453e+39
5.2
15
Bg
171
171
171
171
1.528e+38
0.3
1.628e+38
0.3
3.156e+38
0.7
16
Bu
175
175
175
175
17
Ag
175
179
175
179
1.177e+39
2.5
5.969e+38
1.3
1.774e+39
3.8
18
Bg
179
181
179
185
7.292e+38
1.6
1.223e+39
2.6
1.952e+39
4.2
19
Au
185
185
185
194
20
Au
194
194
195
194
21
Ag
197
197
197
197
5.310e+38
1.1
4.204e+38
0.9
9.514e+38
2.0
22
Bu
198
203
198
203
23
Bg
203
204
203
209
2.308e+38
0.5
3.463e+38
0.7
5.772e+38
1.2
24
Ag
209
209
209
210
1.233e+39
2.6
9.381e+38
2.0
2.171e+39
4.6
25
Bu
214
218
214
220
26
Au
220
220
223
220
27
Bg
224
224
224
224
2.720e+38
0.6
3.881e+38
0.8
6.601e+38
1.4
28
Au
229
229
231
229
29
Ag
234
234
234
234
4.535e+39
9.6
5.172e+38
1.1
5.052e+39
10.7
30
Bu
238
241
238
240
31
Bg
248
248
248
248
6.888e+38
1.5
1.066e+39
2.3
1.754e+39
3.7
32
Ag
250
250
250
250
5.745e+39
12.2
1.000e+39
2.1
6.745e+39
14.3
33
Bu
259
266
259
259
34
Bg
266
269
266
266
2.117e+38
0.5
2.609e+38
0.6
4.726e+38
1.0
35
Au
271
271
272
271
36
Au
273
273
273
273
37
Ag
273
273
273
273
2.039e+39
4.3
2.025e+39
4.3
4.065e+39
8.6
38
Bu
273
282
278
275
39
Bg
282
282
282
282
40
Au
282
287
289
282
3.819e+38
0.8
5.759e+38
1.2
9.577e+38
2.0
41
Bu
289
289
289
289
7.799e+37
0.2
9.559e+37
0.2
1.736e+38
0.4
42
Bg
289
295
295
295
43
Au
295
296
296
296
44
Ag
296
300
300
300
6.015e+38
1.3
5.002e+38
1.1
1.102e+39
2.3
45
Bg
300
311
311
311
1.919e+38
0.4
3.237e+38
0.7
5.156e+38
1.1
46
Bg
311
314
315
315
2.931e+38
0.6
3.452e+38
0.7
6.383e+38
1.4
47
Ag
315
315
321
321
3.589e+39
7.6
6.876e+38
1.5
4.277e+39
9.1
48
Bu
321
364
358
364
49
Ag
364
366
364
373
2.245e+39
4.8
1.293e+39
2.8
3.537e+39
7.5
50
Bu
376
377
376
377
51
Au
377
385
392
378
52
Au
395
395
404
395
53
Bg
404
404
414
404
7.544e+38
1.6
9.125e+38
1.9
1.667e+39
3.5
54
Bg
421
421
421
421
7.438e+38
1.6
1.196e+39
2.5
1.940e+39
4.1
55
Ag
422
422
422
422
1.590e+39
3.4
1.034e+39
2.2
2.624e+39
5.6
56
Bu
427
427
427
427
57
Bu
484
489
484
491
58
Au
491
491
492
494
59
Ag
503
503
503
503
9.454e+38
2.0
7.489e+38
1.6
1.694e+39
3.6
60
Bu
506
508
506
508
61
Au
508
511
511
511
62
Bg
511
523
521
520
1.019e+39
2.2
1.202e+39
2.6
2.220e+39
4.7
63
Au
523
526
526
523
64
Bg
526
526
526
526
1.377e+38
0.3
1.604e+38
0.3
2.981e+38
0.6
65
Ag
526
526
528
526
2.328e+39
5.0
2.500e+39
5.3
4.828e+39
10.3
66
Bu
528
534
533
534
67
Ag
537
537
537
537
1.165e+39
2.5
8.162e+38
1.7
1.981e+39
4.2
68
Bg
547
547
547
547
4.635e+38
1.0
7.822e+38
1.7
1.246e+39
2.7
69
Bu
820
820
820
821
70
Ag
821
821
821
821
2.851e+40
60.6
3.823e+38
0.8
2.889e+40
61.5
71
Au
822
822
829
822
72
Bg
831
831
831
831
1.383e+38
0.3
1.901e+38
0.4
3.284e+38
0.7
73
Ag
832
832
832
832
4.659e+40
99.1
4.134e+38
0.9
4.701e+40
100.0
74
Bu
840
851
840
851
75
Bg
851
852
851
856
2.283e+39
4.9
2.435e+39
5.2
4.718e+39
10.0
76
Au
856
856
857
858
77
Ag
874
874
874
874
2.612e+39
5.6
3.216e+39
6.8
5.828e+39
12.4
78
Bu
879
895
879
895
79
Bg
895
929
895
929
6.191e+38
1.3
1.035e+39
2.2
1.654e+39
3.5
80
Au
929
943
931
939
81
Au
959
959
963
959
82
Ag
963
963
979
963
1.092e+40
23.2
3.872e+39
8.2
1.479e+40
31.5
83
Bg
979
979
981
979
3.588e+38
0.8
6.025e+38
1.3
9.613e+38
2.0
84
Bu
981
997
1038
987
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.