-    PARAKELDYSHITE     -    Na2ZrSi2O7

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. Tetter norm-conserving pseudopotential for Zr. 

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:  P-1 
Lattice parameters (Å):  6.6600  8.8300  5.4200 
Angles (°):  92.75  94.25  72.33 

Symmetry (theoretical): 

Space group:  P-1 
Lattice parameters (Å):  6.4351  8.7176  5.3822 
Angles (°):  92.60  94.32  71.03 

Cell contents: 

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

Atomic positions (theoretical):

Na:  0.8911  0.1066  0.2630 
Na:  0.3479  0.4929  0.7585 
Zr:  0.2947  0.2735  0.2193 
Si:  0.6532  0.1455  0.7751 
Si:  0.9407  0.3363  0.6817 
O:  0.2808  0.0438  0.1746 
O:  0.8926  0.1626  0.7122 
O:  0.4903  0.2137  0.5394 
O:  0.5795  0.2477  0.0288 
O:  0.0026  0.3294  0.3960 
O:  0.1331  0.3399  0.8818 
O:  0.2841  0.5162  0.2852 
Na:  0.1089  0.8934  0.7370 
Na:  0.6521  0.5071  0.2415 
Zr:  0.7053  0.7265  0.7807 
Si:  0.3468  0.8545  0.2249 
Si:  0.0593  0.6637  0.3183 
O:  0.7192  0.9562  0.8254 
O:  0.1074  0.8374  0.2878 
O:  0.5097  0.7863  0.4606 
O:  0.4205  0.7523  0.9712 
O:  0.9974  0.6706  0.6040 
O:  0.8669  0.6601  0.1182 
O:  0.7159  0.4838  0.7148 
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
Ag
58
58
58
58
1.994e+39
3.7
4.673e+38
0.9
2.461e+39
4.6
5
Ag
90
90
90
90
2.514e+39
4.7
2.273e+39
4.2
4.788e+39
8.9
6
Au
94
95
96
102
7
Ag
111
111
111
111
1.991e+39
3.7
8.951e+38
1.7
2.886e+39
5.4
8
Au
112
120
112
120
9
Ag
120
121
120
122
3.058e+39
5.7
2.100e+39
3.9
5.158e+39
9.6
10
Ag
126
126
126
126
4.879e+38
0.9
5.540e+38
1.0
1.042e+39
1.9
11
Ag
129
129
129
129
2.121e+39
4.0
7.847e+38
1.5
2.905e+39
5.4
12
Au
154
154
154
155
13
Ag
155
155
155
157
1.313e+39
2.5
5.769e+38
1.1
1.890e+39
3.5
14
Ag
170
170
170
170
3.045e+39
5.7
7.972e+38
1.5
3.843e+39
7.2
15
Au
173
173
173
173
16
Au
174
175
176
174
17
Ag
176
176
179
176
1.313e+39
2.5
2.189e+38
0.4
1.532e+39
2.9
18
Au
182
186
183
183
19
Ag
195
195
195
195
5.433e+39
10.1
4.878e+38
0.9
5.921e+39
11.1
20
Ag
198
198
198
198
1.084e+39
2.0
1.192e+39
2.2
2.275e+39
4.2
21
Au
199
203
199
201
22
Ag
216
216
216
216
1.719e+39
3.2
6.342e+38
1.2
2.353e+39
4.4
23
Au
217
217
217
217
24
Au
222
224
223
223
25
Au
224
227
228
225
26
Ag
233
233
233
233
8.446e+38
1.6
5.977e+38
1.1
1.442e+39
2.7
27
Ag
243
243
243
243
28
Au
243
243
244
245
3.150e+39
5.9
1.984e+39
3.7
5.134e+39
9.6
29
Ag
260
260
260
260
5.843e+39
10.9
1.448e+39
2.7
7.292e+39
13.6
30
Au
264
267
269
270
31
Ag
270
270
270
270
5.185e+39
9.7
2.022e+38
0.4
5.387e+39
10.1
32
Au
278
279
288
285
33
Au
288
289
298
308
34
Ag
308
308
308
311
3.203e+39
6.0
4.737e+38
0.9
3.677e+39
6.9
35
Au
319
319
319
323
36
Au
326
332
327
332
37
Ag
332
334
332
333
2.103e+40
39.3
3.341e+39
6.2
2.438e+40
45.5
38
Au
334
348
348
348
39
Ag
348
356
355
355
7.665e+39
14.3
1.913e+39
3.6
9.578e+39
17.9
40
Au
357
368
368
357
41
Ag
368
375
376
368
3.435e+38
0.6
2.211e+38
0.4
5.646e+38
1.1
42
Ag
376
376
382
376
2.817e+40
52.6
7.651e+39
14.3
3.583e+40
66.9
43
Au
410
411
410
411
44
Au
411
413
412
413
45
Ag
413
419
413
422
2.032e+40
37.9
5.151e+39
9.6
2.547e+40
47.6
46
Ag
422
422
422
436
1.605e+39
3.0
2.054e+39
3.8
3.659e+39
6.8
47
Au
448
469
466
465
48
Ag
469
471
469
469
9.702e+38
1.8
5.739e+38
1.1
1.544e+39
2.9
49
Au
490
499
499
494
50
Ag
499
503
508
499
5.383e+39
10.1
1.497e+39
2.8
6.880e+39
12.8
51
Au
540
541
541
541
52
Ag
541
541
543
541
4.304e+39
8.0
1.455e+39
2.7
5.758e+39
10.8
53
Au
554
563
556
554
54
Ag
568
568
568
568
7.780e+38
1.5
1.181e+39
2.2
1.959e+39
3.7
55
Au
591
595
595
591
56
Ag
595
598
599
595
1.962e+39
3.7
2.188e+39
4.1
4.151e+39
7.7
57
Au
689
692
696
690
58
Ag
718
718
718
718
1.043e+40
19.5
6.467e+38
1.2
1.108e+40
20.7
59
Ag
843
843
843
843
2.119e+39
4.0
2.385e+39
4.5
4.504e+39
8.4
60
Au
858
883
861
860
61
Au
891
900
901
901
62
Ag
901
901
917
905
2.759e+40
51.5
2.597e+40
48.5
5.356e+40
100.0
63
Ag
918
918
918
918
2.610e+39
4.9
2.134e+39
4.0
4.744e+39
8.9
64
Au
920
921
922
920
65
Au
922
931
931
929
66
Ag
931
951
943
931
1.214e+40
22.7
1.564e+40
29.2
2.779e+40
51.9
67
Au
966
972
972
972
68
Ag
972
975
975
975
3.426e+39
6.4
3.374e+39
6.3
6.800e+39
12.7
69
Ag
975
982
975
982
2.550e+40
47.6
2.749e+40
51.3
5.299e+40
98.9
70
Au
985
1017
1017
1017
71
Ag
1017
1030
1035
1080
1.780e+40
33.2
2.126e+40
39.7
3.906e+40
72.9
72
Au
1085
1092
1122
1112
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.