-    GYPSUM     -    CaSO42(H2O)

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:  15  C2/c 
Lattice parameters (Å):  3.3216  8.0334  3.0015 
Angles (°):  90  114.11  90 

Symmetry (theoretical): 

Space group:  15  C2/c 
Lattice parameters (Å):  8.1627  8.1627  5.6647 
Angles (°):  80.91  99.08  45.67 

Cell contents: 

Number of atoms:  24 
Number of atom types: 
Chemical composition: 

Atomic positions (theoretical):

Ca:  0.1682  0.1682  0.2500 
S:  0.3299  0.3299  0.7500 
O:  0.3600  0.1889  0.5930 
O:  0.5835  0.1877  0.9157 
O:  0.8623  0.2727  0.9146 
H:  0.8353  0.3399  0.7340 
H:  0.7629  0.2445  0.9083 
O:  0.1889  0.3600  0.9070 
O:  0.1877  0.5835  0.5843 
O:  0.2727  0.8623  0.5854 
H:  0.3399  0.8353  0.7660 
H:  0.2445  0.7629  0.5917 
Ca:  0.8318  0.8318  0.7500 
S:  0.6701  0.6701  0.2500 
O:  0.6400  0.8111  0.4070 
O:  0.4165  0.8123  0.0843 
O:  0.1377  0.7273  0.0854 
H:  0.1647  0.6601  0.2660 
H:  0.2371  0.7555  0.0917 
O:  0.8111  0.6400  0.0930 
O:  0.8123  0.4165  0.4157 
O:  0.7273  0.1377  0.4146 
H:  0.6601  0.1647  0.2340 
H:  0.7555  0.2371  0.4083 
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
Bg
92
92
92
92
2.545e+38
0.2
2.752e+38
0.2
5.297e+38
0.4
5
Bu
95
96
95
95
6
Ag
103
103
103
103
1.262e+39
0.9
9.725e+38
0.7
2.234e+39
1.5
7
Au
106
106
107
106
8
Bg
113
113
113
113
6.536e+37
0.0
8.987e+37
0.1
1.552e+38
0.1
9
Bu
113
117
113
113
10
Bg
117
129
117
117
5.954e+38
0.4
7.182e+38
0.5
1.314e+39
0.9
11
Ag
129
131
129
129
8.768e+38
0.6
7.485e+38
0.5
1.625e+39
1.1
12
Ag
139
139
139
139
1.758e+39
1.2
2.004e+39
1.4
3.762e+39
2.5
13
Bg
145
145
145
145
1.840e+38
0.1
2.734e+38
0.2
4.574e+38
0.3
14
Bg
158
158
158
158
5.923e+38
0.4
7.299e+38
0.5
1.322e+39
0.9
15
Bu
169
170
169
170
16
Au
170
170
172
172
17
Bg
172
172
173
175
5.596e+38
0.4
9.422e+38
0.6
1.502e+39
1.0
18
Ag
184
184
184
184
3.263e+39
2.2
1.486e+39
1.0
4.748e+39
3.2
19
Bu
187
189
187
192
20
Au
196
196
200
196
21
Bg
200
200
206
200
6.147e+38
0.4
6.583e+38
0.4
1.273e+39
0.9
22
Bu
206
220
211
207
23
Ag
220
226
220
220
8.592e+38
0.6
4.549e+38
0.3
1.314e+39
0.9
24
Au
226
230
230
226
25
Bg
230
231
232
230
5.977e+38
0.4
8.792e+38
0.6
1.477e+39
1.0
26
Bu
232
272
247
266
27
Au
335
335
345
335
28
Bu
345
345
348
351
29
Ag
351
351
351
352
1.219e+39
0.8
8.514e+38
0.6
2.070e+39
1.4
30
Bg
360
360
360
360
3.708e+38
0.3
4.388e+38
0.3
8.096e+38
0.5
31
Ag
400
400
400
400
8.743e+39
5.9
6.617e+39
4.5
1.536e+40
10.4
32
Au
403
403
404
403
33
Ag
470
470
470
470
8.097e+39
5.5
6.161e+39
4.2
1.426e+40
9.6
34
Au
479
479
479
479
35
Bu
480
512
480
481
36
Bg
542
542
542
542
1.895e+39
1.3
2.244e+39
1.5
4.140e+39
2.8
37
Au
548
548
548
548
38
Bu
552
571
552
555
39
Ag
582
582
582
582
5.503e+39
3.7
5.698e+39
3.9
1.120e+40
7.6
40
Au
587
587
593
587
41
Bg
593
593
593
593
2.996e+39
2.0
4.674e+39
3.2
7.670e+39
5.2
42
Bu
614
619
614
623
43
Bg
637
637
637
637
1.761e+39
1.2
1.919e+39
1.3
3.680e+39
2.5
44
Ag
646
646
646
646
2.170e+39
1.5
1.634e+39
1.1
3.804e+39
2.6
45
Bu
648
657
648
650
46
Bg
657
669
657
657
1.197e+39
0.8
1.851e+39
1.3
3.048e+39
2.1
47
Bg
669
674
669
669
3.722e+38
0.3
4.302e+38
0.3
8.024e+38
0.5
48
Au
674
683
683
674
49
Ag
683
686
685
683
8.821e+38
0.6
6.750e+38
0.5
1.557e+39
1.1
50
Bu
715
717
715
719
51
Au
736
736
740
736
52
Ag
762
762
762
762
2.328e+39
1.6
1.210e+39
0.8
3.538e+39
2.4
53
Au
972
972
974
972
54
Ag
977
977
977
977
1.259e+41
85.1
5.519e+37
0.0
1.259e+41
85.2
55
Bg
1073
1073
1073
1073
6.959e+39
4.7
7.400e+39
5.0
1.436e+40
9.7
56
Bu
1074
1077
1074
1092
57
Au
1092
1092
1122
1114
58
Ag
1122
1122
1122
1122
4.478e+39
3.0
5.645e+39
3.8
1.012e+40
6.8
59
Bu
1122
1128
1128
1128
60
Bg
1128
1191
1167
1151
1.160e+40
7.8
1.895e+40
12.8
3.056e+40
20.7
61
Bu
1566
1566
1566
1576
62
Ag
1579
1579
1579
1579
7.108e+38
0.5
4.414e+38
0.3
1.152e+39
0.8
63
Bg
1641
1641
1641
1641
1.290e+38
0.1
1.907e+38
0.1
3.198e+38
0.2
64
Au
1644
1644
1647
1644
65
Bg
3263
3263
3263
3263
8.024e+39
5.4
1.322e+40
8.9
2.125e+40
14.4
66
Bu
3264
3264
3264
3264
67
Bu
3264
3265
3264
3276
68
Ag
3276
3276
3276
3331
9.876e+40
66.8
2.348e+40
15.9
1.222e+41
82.7
69
Bu
3372
3377
3372
3372
70
Ag
3378
3378
3378
3378
1.267e+41
85.7
2.121e+40
14.3
1.479e+41
100.0
71
Bg
3391
3391
3391
3391
1.053e+40
7.1
1.148e+40
7.8
2.200e+40
14.9
72
Au
3427
3427
3492
3427
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.