-    FRESNOITE     -    Ba2ZrSi2O8

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:  100  P4bm 
Lattice parameters (Å):  8.5200  8.5200  5.2100 
Angles (°):  90  90  90 

Symmetry (theoretical): 

Space group:  100  P4bm 
Lattice parameters (Å):  8.6822  8.6822  4.9850 
Angles (°):  90  90  90 

Cell contents: 

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

Atomic positions (theoretical):

Ba:  0.3261  0.8261  0.0068 
Si:  0.1245  0.6245  0.5244 
Zr:  0.0000  0.0000  0.5458 
O:  0.0000  0.5000  0.6466 
O:  0.1235  0.6235  0.2079 
O:  0.2850  0.5748  0.6613 
O:  0.0000  0.0000  0.1719 
Ba:  0.1739  0.3261  0.0068 
Si:  0.3755  0.1245  0.5244 
O:  0.5000  0.0000  0.6466 
O:  0.3765  0.1235  0.2079 
O:  0.4252  0.2850  0.6613 
Ba:  0.8261  0.6739  0.0068 
Si:  0.6245  0.8755  0.5244 
Zr:  0.5000  0.5000  0.5458 
O:  0.6235  0.8765  0.2079 
O:  0.7850  0.9252  0.6613 
O:  0.5000  0.5000  0.1719 
Ba:  0.6739  0.1739  0.0068 
Si:  0.8755  0.3755  0.5244 
O:  0.8765  0.3765  0.2079 
O:  0.7150  0.4252  0.6613 
O:  0.0748  0.7850  0.6613 
O:  0.9252  0.2150  0.6613 
O:  0.5748  0.7150  0.6613 
O:  0.2150  0.0748  0.6613 
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
E
37
37
37
37
9.536e+39
4.5
1.311e+40
6.2
2.265e+40
10.7
5
E
37
46
46
37
9.536e+39
4.5
1.311e+40
6.2
2.265e+40
10.7
6
B1
46
67
67
46
3.266e+38
0.2
2.449e+38
0.1
5.715e+38
0.3
7
A2
76
76
76
76
8
E
80
80
80
80
4.517e+38
0.2
6.211e+38
0.3
1.073e+39
0.5
9
E
80
82
82
80
4.518e+38
0.2
6.212e+38
0.3
1.073e+39
0.5
10
E
94
94
94
94
3.623e+39
1.7
4.981e+39
2.3
8.604e+39
4.0
11
E
94
94
94
94
3.623e+39
1.7
4.981e+39
2.3
8.604e+39
4.0
12
B2
96
96
96
96
2.203e+38
0.1
3.029e+38
0.1
5.233e+38
0.2
13
A1
97
97
97
97
8.821e+38
0.4
3.375e+37
0.0
9.159e+38
0.4
14
A2
105
105
105
105
15
E
107
107
107
107
4.659e+38
0.2
6.406e+38
0.3
1.107e+39
0.5
16
E
107
116
116
107
4.659e+38
0.2
6.406e+38
0.3
1.106e+39
0.5
17
A1
130
130
130
133
4.489e+39
2.1
1.883e+39
0.9
6.372e+39
3.0
18
A2
133
133
133
139
19
B2
139
139
139
146
2.091e+38
0.1
2.875e+38
0.1
4.965e+38
0.2
20
E
146
146
146
146
2.305e+38
0.1
3.169e+38
0.1
5.474e+38
0.3
21
E
146
146
146
147
2.305e+38
0.1
3.169e+38
0.1
5.474e+38
0.3
22
B2
147
147
147
148
1.433e+39
0.7
1.971e+39
0.9
3.404e+39
1.6
23
B1
157
157
157
157
4.374e+39
2.1
3.281e+39
1.5
7.655e+39
3.6
24
E
160
160
160
160
5.508e+38
0.3
7.574e+38
0.4
1.308e+39
0.6
25
E
160
169
169
160
5.508e+38
0.3
7.573e+38
0.4
1.308e+39
0.6
26
E
182
182
182
182
8.905e+39
4.2
1.224e+40
5.8
2.115e+40
10.0
27
E
182
184
184
182
8.905e+39
4.2
1.224e+40
5.8
2.115e+40
10.0
28
A2
194
194
194
194
29
E
196
196
196
196
1.086e+40
5.1
1.494e+40
7.0
2.580e+40
12.1
30
E
196
198
198
196
1.086e+40
5.1
1.494e+40
7.0
2.580e+40
12.1
31
A1
198
198
198
222
3.999e+38
0.2
5.162e+37
0.0
4.516e+38
0.2
32
E
227
227
227
227
4.254e+39
2.0
5.849e+39
2.8
1.010e+40
4.8
33
E
227
234
234
227
4.254e+39
2.0
5.849e+39
2.8
1.010e+40
4.8
34
A1
234
234
234
241
7.604e+38
0.4
1.734e+38
0.1
9.337e+38
0.4
35
B2
256
256
256
256
3.722e+39
1.8
5.117e+39
2.4
8.839e+39
4.2
36
A1
260
260
260
260
6.836e+37
0.0
4.822e+37
0.0
1.166e+38
0.1
37
E
279
279
279
279
3.597e+39
1.7
4.945e+39
2.3
8.542e+39
4.0
38
E
279
288
288
279
3.597e+39
1.7
4.945e+39
2.3
8.542e+39
4.0
39
E
298
298
298
298
1.909e+39
0.9
2.625e+39
1.2
4.533e+39
2.1
40
E
298
299
299
298
1.909e+39
0.9
2.625e+39
1.2
4.533e+39
2.1
41
B1
300
300
300
300
7.969e+39
3.8
5.977e+39
2.8
1.395e+40
6.6
42
E
329
329
329
329
1.101e+38
0.1
1.514e+38
0.1
2.616e+38
0.1
43
E
329
345
345
329
1.101e+38
0.1
1.514e+38
0.1
2.615e+38
0.1
44
B2
370
370
370
370
2.715e+39
1.3
3.733e+39
1.8
6.448e+39
3.0
45
B1
376
376
376
376
1.608e+39
0.8
1.206e+39
0.6
2.814e+39
1.3
46
E
379
379
379
379
4.122e+39
1.9
5.668e+39
2.7
9.790e+39
4.6
47
E
379
420
420
379
4.122e+39
1.9
5.668e+39
2.7
9.790e+39
4.6
48
A2
425
425
425
425
49
B2
443
443
443
443
7.670e+37
0.0
1.055e+38
0.0
1.822e+38
0.1
50
A1
452
452
452
456
3.983e+39
1.9
1.120e+38
0.1
4.095e+39
1.9
51
E
456
456
456
456
1.138e+38
0.1
1.565e+38
0.1
2.704e+38
0.1
52
E
456
480
480
456
1.138e+38
0.1
1.565e+38
0.1
2.704e+38
0.1
53
B1
480
491
491
480
6.462e+39
3.0
4.846e+39
2.3
1.131e+40
5.3
54
A2
499
499
499
499
55
E
528
528
528
528
4.424e+38
0.2
6.083e+38
0.3
1.051e+39
0.5
56
E
528
528
528
528
4.424e+38
0.2
6.083e+38
0.3
1.051e+39
0.5
57
E
560
560
560
560
2.875e+38
0.1
3.953e+38
0.2
6.827e+38
0.3
58
E
560
561
561
560
2.875e+38
0.1
3.953e+38
0.2
6.827e+38
0.3
59
B2
563
563
563
563
1.667e+39
0.8
2.292e+39
1.1
3.959e+39
1.9
60
A1
568
568
568
592
2.362e+40
11.1
2.788e+38
0.1
2.390e+40
11.3
61
A1
664
664
664
665
2.528e+40
11.9
1.626e+37
0.0
2.530e+40
11.9
62
B2
673
673
673
673
1.306e+39
0.6
1.795e+39
0.8
3.101e+39
1.5
63
A2
702
702
702
702
64
A1
705
705
705
737
2.105e+41
99.1
1.909e+39
0.9
2.124e+41
100.0
65
E
876
876
876
876
3.800e+38
0.2
5.224e+38
0.2
9.024e+38
0.4
66
E
876
884
884
876
3.800e+38
0.2
5.224e+38
0.2
9.024e+38
0.4
67
B1
908
908
908
908
9.151e+39
4.3
6.863e+39
3.2
1.601e+40
7.5
68
E
920
920
920
920
4.796e+39
2.3
6.594e+39
3.1
1.139e+40
5.4
69
E
920
938
938
920
4.796e+39
2.3
6.594e+39
3.1
1.139e+40
5.4
70
B2
938
954
954
938
1.011e+39
0.5
1.390e+39
0.7
2.401e+39
1.1
71
A1
954
958
958
968
3.709e+40
17.5
2.815e+37
0.0
3.712e+40
17.5
72
E
971
971
971
971
9.060e+37
0.0
1.246e+38
0.1
2.152e+38
0.1
73
E
971
1003
1003
971
9.060e+37
0.0
1.246e+38
0.1
2.152e+38
0.1
74
B2
1003
1011
1011
1003
2.863e+39
1.3
3.936e+39
1.9
6.798e+39
3.2
75
E
1025
1025
1025
1025
7.254e+37
0.0
9.974e+37
0.0
1.723e+38
0.1
76
E
1025
1032
1032
1025
7.254e+37
0.0
9.974e+37
0.0
1.723e+38
0.1
77
A2
1033
1033
1033
1033
78
A1
1034
1034
1034
1078
3.363e+39
1.6
1.311e+39
0.6
4.673e+39
2.2
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.