-    GLAUBERITE     -    Na2Ca(SO4)2

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):  10.1580  8.3330  8.5510 
Angles (°):  90  112.333  90 

Symmetry (theoretical): 

Space group:  15  C2/c 
Lattice parameters (Å):  6.5509  6.5509  8.5659 
Angles (°):  73.52  106.47  102.01 

Cell contents: 

Number of atoms:  26 
Number of atom types:  4 
Chemical composition:  0 

Atomic positions (theoretical):

Na:  0.4159  0.6993  0.0582 
Ca:  0.0569  0.0569  0.2500 
S:  0.6003  0.9632  0.3159 
O:  0.4339  0.0984  0.2877 
O:  0.6669  0.9962  0.1573 
O:  0.5185  0.7338  0.3702 
O:  0.7943  0.0316  0.4384 
Na:  0.6993  0.4159  0.4418 
S:  0.9632  0.6003  0.1841 
O:  0.0984  0.4339  0.2123 
O:  0.9962  0.6669  0.3427 
O:  0.7338  0.5185  0.1298 
O:  0.0316  0.7943  0.0616 
Na:  0.5841  0.3007  0.9418 
Ca:  0.9431  0.9431  0.7500 
S:  0.3997  0.0368  0.6841 
O:  0.5661  0.9016  0.7123 
O:  0.3331  0.0038  0.8427 
O:  0.4815  0.2662  0.6298 
O:  0.2057  0.9684  0.5616 
Na:  0.3007  0.5841  0.5582 
S:  0.0368  0.3997  0.8159 
O:  0.9016  0.5661  0.7877 
O:  0.0038  0.3331  0.6573 
O:  0.2662  0.4815  0.8702 
O:  0.9684  0.2057  0.9384 
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
Bu
60
62
60
62
5
Ag
72
72
72
72
1.172e+39
0.7
2.566e+38
0.2
1.428e+39
0.9
6
Bg
74
74
74
74
2.137e+38
0.1
2.381e+38
0.1
4.518e+38
0.3
7
Bu
79
86
79
82
8
Au
86
86
86
86
9
Ag
86
86
88
86
1.297e+38
0.1
6.801e+37
0.0
1.977e+38
0.1
10
Bg
88
88
95
88
7.008e+38
0.4
8.058e+38
0.5
1.507e+39
0.9
11
Ag
97
97
97
97
1.176e+39
0.7
9.484e+38
0.6
2.125e+39
1.3
12
Bg
102
102
102
102
9.925e+38
0.6
1.605e+39
1.0
2.597e+39
1.6
13
Au
107
107
108
107
14
Au
110
110
111
110
15
Bg
111
111
113
111
7.899e+36
0.0
1.323e+37
0.0
2.113e+37
0.0
16
Bu
113
116
113
113
17
Au
116
119
119
116
18
Ag
119
120
120
119
3.181e+38
0.2
2.738e+38
0.2
5.918e+38
0.4
19
Bg
120
123
127
120
6.525e+37
0.0
8.127e+37
0.1
1.465e+38
0.1
20
Ag
129
129
129
129
3.255e+38
0.2
2.314e+38
0.1
5.569e+38
0.3
21
Bu
130
133
130
133
22
Au
133
136
134
136
23
Bg
136
137
136
150
2.350e+38
0.1
3.814e+38
0.2
6.164e+38
0.4
24
Ag
150
150
150
152
3.330e+38
0.2
2.915e+38
0.2
6.245e+38
0.4
25
Bu
154
157
154
157
26
Au
157
158
158
159
27
Bg
169
169
169
169
8.658e+37
0.1
1.363e+38
0.1
2.229e+38
0.1
28
Bu
171
178
171
175
29
Ag
184
184
184
184
8.413e+38
0.5
1.917e+37
0.0
8.605e+38
0.5
30
Bg
185
185
185
185
2.310e+37
0.0
3.177e+37
0.0
5.487e+37
0.0
31
Bu
185
186
185
186
32
Ag
186
191
186
187
1.254e+39
0.8
5.786e+38
0.4
1.832e+39
1.2
33
Bg
195
195
195
195
5.018e+38
0.3
8.069e+38
0.5
1.309e+39
0.8
34
Ag
203
203
204
203
5.958e+38
0.4
4.119e+38
0.3
1.008e+39
0.6
35
Au
204
204
204
204
8.632e+37
0.1
5.822e+37
0.0
1.445e+38
0.1
36
Bu
204
209
207
213
37
Bg
213
213
213
216
7.031e+37
0.0
1.151e+38
0.1
1.854e+38
0.1
38
Au
216
216
228
247
39
Bg
273
273
273
273
2.005e+38
0.1
2.231e+38
0.1
4.236e+38
0.3
40
Bu
277
282
277
282
41
Au
282
287
287
287
42
Ag
287
327
329
289
3.475e+38
0.2
6.190e+37
0.0
4.094e+38
0.3
43
Bg
421
421
421
421
7.964e+38
0.5
1.344e+39
0.8
2.140e+39
1.3
44
Bu
426
426
426
426
45
Ag
426
427
426
426
6.197e+39
3.9
6.959e+39
4.4
1.316e+40
8.3
46
Au
429
429
429
429
47
Bg
456
456
456
456
5.382e+39
3.4
7.995e+39
5.0
1.338e+40
8.4
48
Bu
461
461
461
461
49
Ag
469
469
469
469
2.115e+39
1.3
1.382e+39
0.9
3.497e+39
2.2
50
Au
477
477
477
477
51
Bu
579
579
579
583
52
Au
583
583
584
588
53
Ag
588
588
588
590
4.281e+39
2.7
3.424e+39
2.1
7.705e+39
4.8
54
Bg
594
594
594
594
1.688e+39
1.1
2.826e+39
1.8
4.514e+39
2.8
55
Bu
606
613
606
606
56
Au
613
613
613
613
57
Ag
613
615
615
613
1.079e+39
0.7
8.360e+38
0.5
1.915e+39
1.2
58
Bg
615
618
619
615
9.256e+38
0.6
9.837e+38
0.6
1.909e+39
1.2
59
Au
619
619
623
619
60
Ag
623
623
626
623
3.303e+39
2.1
3.030e+39
1.9
6.333e+39
4.0
61
Bu
626
627
627
626
62
Bg
627
627
629
627
3.306e+39
2.1
3.987e+39
2.5
7.293e+39
4.6
63
Au
968
968
968
968
64
Bu
970
970
970
970
65
Bg
972
972
972
972
5.292e+38
0.3
5.713e+38
0.4
1.101e+39
0.7
66
Ag
973
973
973
973
1.592e+41
100.0
7.418e+37
0.0
1.593e+41
100.0
67
Bu
1054
1059
1054
1073
68
Au
1073
1073
1075
1077
69
Ag
1077
1077
1077
1106
4.522e+39
2.8
3.424e+39
2.1
7.947e+39
5.0
70
Au
1106
1106
1114
1107
71
Bg
1114
1114
1122
1114
1.235e+38
0.1
1.316e+38
0.1
2.551e+38
0.2
72
Bu
1122
1126
1130
1124
73
Bu
1130
1130
1130
1130
74
Ag
1130
1138
1138
1138
1.326e+40
8.3
9.479e+39
6.0
2.274e+40
14.3
75
Bg
1138
1139
1139
1139
7.709e+39
4.8
8.881e+39
5.6
1.659e+40
10.4
76
Ag
1139
1145
1145
1145
3.003e+39
1.9
1.943e+39
1.2
4.945e+39
3.1
77
Au
1145
1147
1147
1147
78
Bg
1147
1210
1191
1159
4.510e+39
2.8
5.934e+39
3.7
1.044e+40
6.6
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.