-    ARCANITE     -    K2SO4

The crystal structure is fully relaxed (both unit cell parameters and atomic positions under symmetry constraints) starting from an experimental structure similar to the one reported in 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:  62  Pnma 
Lattice parameters (Å):  3.9561  5.3293  3.0496 
Angles (°):  90.0  90.0  90.0 

Symmetry (theoretical): 

Space group:  62  Pnma 
Lattice parameters (Å):  6.9316  10.3457  5.2633 
Angles (°):  90.0  90.0  90.0 

Cell contents: 

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

Atomic positions (theoretical):

K:  0.6582  0.4504  0.2500 
K:  0.0029  0.6646  0.2500 
S:  0.2264  0.4068  0.2500 
O:  0.0136  0.4142  0.2500 
O:  0.3072  0.5394  0.2500 
O:  0.2984  0.3399  0.0213 
K:  0.1582  0.0496  0.7500 
K:  0.5029  0.8354  0.7500 
S:  0.7264  0.0932  0.7500 
O:  0.5136  0.0858  0.7500 
O:  0.8072  0.9606  0.7500 
O:  0.7984  0.1601  0.9787 
K:  0.3418  0.5496  0.7500 
K:  0.9971  0.3354  0.7500 
S:  0.7736  0.5932  0.7500 
O:  0.9864  0.5858  0.7500 
O:  0.6928  0.4606  0.7500 
O:  0.7016  0.6601  0.5213 
K:  0.8418  0.9504  0.2500 
K:  0.4971  0.1646  0.2500 
S:  0.2736  0.9068  0.2500 
O:  0.4864  0.9142  0.2500 
O:  0.1928  0.0394  0.2500 
O:  0.2016  0.8399  0.4787 
O:  0.7016  0.6601  0.9787 
O:  0.2016  0.8399  0.0213 
O:  0.2984  0.3399  0.4787 
O:  0.7984  0.1601  0.5213 
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
Au
25
25
25
25
5
B2g
32
32
32
32
6
B1g
50
50
50
50
3.639e+37
0.0
5.004e+37
0.0
8.644e+37
0.1
7
B2u
63
63
68
63
8
A1g
75
75
75
75
5.038e+38
0.4
1.679e+38
0.1
6.717e+38
0.5
9
B3u
78
78
78
78
10
B3g
90
90
90
90
8.905e+37
0.1
1.224e+38
0.1
2.115e+38
0.2
11
B1u
101
101
101
101
12
Ag
101
101
101
110
5.414e+38
0.4
4.907e+37
0.0
5.905e+38
0.5
13
Au
122
122
122
122
14
B2g
124
124
124
124
15
A1g
131
131
131
131
2.477e+38
0.2
2.018e+37
0.0
2.678e+38
0.2
16
B3g
134
134
134
134
1.971e+38
0.2
2.710e+38
0.2
4.680e+38
0.4
17
B2u
140
140
144
140
18
B1g
144
144
149
144
1.833e+37
0.0
2.520e+37
0.0
4.353e+37
0.0
19
B2g
151
151
151
151
1.340e+37
0.0
1.843e+37
0.0
3.183e+37
0.0
20
A1g
152
152
152
152
1.210e+38
0.1
5.735e+37
0.0
1.783e+38
0.1
21
B1u
157
157
157
158
22
B3g
158
158
158
158
1.734e+36
0.0
2.384e+36
0.0
4.119e+36
0.0
23
B3u
158
158
158
159
24
Au
159
159
159
160
25
B1g
160
160
160
162
2.541e+37
0.0
3.494e+37
0.0
6.035e+37
0.0
26
B1u
181
181
181
182
27
B1g
182
182
182
184
3.312e+37
0.0
4.554e+37
0.0
7.866e+37
0.1
28
B3u
184
185
184
185
29
B2u
185
189
189
189
30
Au
189
189
191
192
31
B2g
192
192
192
198
1.024e+36
0.0
1.408e+36
0.0
2.431e+36
0.0
32
B3g
198
198
198
200
4.136e+37
0.0
5.687e+37
0.0
9.824e+37
0.1
33
A1g
200
200
200
200
3.983e+38
0.3
5.993e+37
0.0
4.582e+38
0.4
34
B3u
202
203
202
202
35
B1g
203
210
203
203
1.299e+38
0.1
1.785e+38
0.1
3.084e+38
0.2
36
B2u
213
213
215
213
37
Au
221
221
221
221
38
B3u
222
223
222
222
39
B1g
224
224
224
224
40
B2u
225
225
232
225
41
B3g
232
232
243
232
4.675e+37
0.0
6.429e+37
0.0
1.110e+38
0.1
42
B1u
243
243
243
250
43
B2g
250
250
250
251
6.032e+36
0.0
8.293e+36
0.0
1.432e+37
0.0
44
A1g
251
251
251
265
3.974e+38
0.3
5.236e+37
0.0
4.498e+38
0.3
45
A1g
265
265
265
265
3.373e+38
0.3
6.694e+37
0.1
4.042e+38
0.3
46
B2u
269
269
272
269
47
B1g
272
272
277
272
9.381e+37
0.1
1.290e+38
0.1
2.228e+38
0.2
48
B3u
278
304
278
278
49
Au
445
445
445
445
50
B1u
446
446
446
446
51
B3g
451
451
451
451
1.036e+39
0.8
1.424e+39
1.1
2.460e+39
1.9
52
B2g
453
453
453
453
4.734e+39
3.7
6.509e+39
5.0
1.124e+40
8.7
53
B3u
486
486
486
486
54
B1g
489
489
489
489
4.542e+39
3.5
6.246e+39
4.8
1.079e+40
8.4
55
Ag
489
489
489
489
2.191e+39
1.7
1.550e+39
1.2
3.741e+39
2.9
56
B2u
491
491
491
491
57
B1u
603
603
604
603
58
B2u
604
604
604
604
59
Au
604
604
607
607
60
A1g
607
607
609
609
4.347e+39
3.4
3.118e+39
2.4
7.465e+39
5.8
61
B2g
609
609
610
610
1.213e+39
0.9
1.668e+39
1.3
2.882e+39
2.2
62
B3g
610
610
610
610
2.805e+39
2.2
3.857e+39
3.0
6.662e+39
5.2
63
B3u
610
611
612
612
64
B1g
612
612
615
618
9.373e+38
0.7
1.289e+39
1.0
2.226e+39
1.7
65
B3u
632
632
632
632
66
B2u
632
638
634
632
67
A1g
638
643
638
638
4.916e+39
3.8
3.595e+39
2.8
8.510e+39
6.6
68
B1g
643
645
643
643
1.512e+37
0.0
2.080e+37
0.0
3.592e+37
0.0
69
B1g
965
965
965
965
1.291e+41
99.9
8.797e+37
0.1
1.292e+41
100.0
70
Ag
965
965
965
965
1.273e+37
0.0
1.750e+37
0.0
3.023e+37
0.0
71
B3u
965
965
965
965
72
B2u
965
965
965
965
73
A1g
1101
1101
1101
1101
3.814e+39
3.0
2.631e+39
2.0
6.445e+39
5.0
74
B2u
1109
1109
1115
1109
75
B1u
1115
1115
1116
1116
76
B2g
1116
1116
1116
1116
1.883e+39
1.5
2.589e+39
2.0
4.472e+39
3.5
77
B1g
1116
1116
1117
1117
1.980e+39
1.5
2.722e+39
2.1
4.701e+39
3.6
78
B3u
1117
1123
1123
1123
79
Au
1123
1126
1126
1126
80
B3g
1126
1144
1136
1144
3.540e+39
2.7
4.867e+39
3.8
8.407e+39
6.5
81
A1g
1144
1145
1144
1145
4.981e+39
3.9
3.616e+39
2.8
8.597e+39
6.7
82
B2u
1145
1170
1170
1170
83
B1g
1170
1175
1177
1177
2.091e+38
0.2
2.875e+38
0.2
4.965e+38
0.4
84
B3u
1177
1194
1183
1185
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.