-    NATISITE     -    Na2TiO4SiO4

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:  129  P4/nmm 
Lattice parameters (Å):  6.4850  6.4850  5.0987 
Angles (°):  90  90  90 

Symmetry (theoretical): 

Space group:  129  P4/nmm 
Lattice parameters (Å):  6.4719  6.4719  5.1194 
Angles (°):  90  90  90 

Cell contents: 

Number of atoms:  18 
Number of atom types: 
Chemical composition: 

Atomic positions (theoretical):

Na:  0.2500  0.2500  0.5000 
Ti:  0.5000  0.0000  0.9348 
Si:  0.0000  0.0000  0.0000 
O:  0.2072  0.0000  0.8191 
O:  0.5000  0.0000  0.2686 
Na:  0.7500  0.7500  0.5000 
O:  0.7928  0.0000  0.8191 
Na:  0.2500  0.7500  0.5000 
Si:  0.5000  0.5000  0.0000 
O:  0.5000  0.7072  0.8191 
Na:  0.7500  0.2500  0.5000 
O:  0.5000  0.2928  0.8191 
Ti:  0.0000  0.5000  0.0652 
O:  0.2928  0.5000  0.1809 
O:  0.0000  0.5000  0.7314 
O:  0.7072  0.5000  0.1809 
O:  0.0000  0.7928  0.1809 
O:  0.0000  0.2072  0.1809 
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
B1u
63
63
63
63
5
Eu
94
94
94
94
6
Eu
94
106
106
94
7
Eg
144
144
144
144
6.477e+38
0.2
8.905e+38
0.3
1.538e+39
0.5
8
Eg
144
144
144
144
6.477e+38
0.2
8.905e+38
0.3
1.538e+39
0.5
9
A1u
144
144
144
144
10
A2u
161
161
161
176
11
B1g
176
176
176
185
1.780e+40
6.0
1.335e+40
4.5
3.115e+40
10.6
12
A2g
185
185
185
193
13
Eu
193
193
193
193
14
Eu
193
193
193
194
15
A1g
213
213
213
213
2.730e+39
0.9
8.276e+38
0.3
3.557e+39
1.2
16
Eu
226
226
226
226
17
Eu
226
226
226
226
18
B1u
228
228
228
228
19
B2u
236
236
236
236
20
Eg
243
243
243
243
4.619e+39
1.6
6.351e+39
2.2
1.097e+40
3.7
21
Eg
243
243
243
243
4.619e+39
1.6
6.351e+39
2.2
1.097e+40
3.7
22
Eu
252
252
252
252
23
Eu
252
252
252
252
24
Eg
255
255
255
255
7.198e+39
2.4
9.897e+39
3.4
1.709e+40
5.8
25
Eg
255
255
255
255
7.198e+39
2.4
9.897e+39
3.4
1.709e+40
5.8
26
A2u
295
295
295
304
27
A2u
307
307
307
319
28
Eu
319
319
319
319
29
Eu
319
320
320
335
30
A1u
347
347
347
347
31
Eu
360
360
360
360
32
Eu
360
368
368
360
33
B1u
368
388
388
368
34
Eg
388
388
388
388
1.023e+40
3.5
1.406e+40
4.8
2.429e+40
8.2
35
Eg
388
441
441
388
1.023e+40
3.5
1.406e+40
4.8
2.429e+40
8.2
36
B2u
441
457
457
441
37
B2g
457
493
493
457
3.525e+39
1.2
4.847e+39
1.6
8.372e+39
2.8
38
Eu
501
501
501
501
39
Eu
501
507
507
501
40
A1g
507
523
523
507
3.347e+40
11.4
1.533e+39
0.5
3.500e+40
11.9
41
Eg
529
529
529
529
1.531e+39
0.5
2.148e+39
0.7
3.678e+39
1.2
42
Eg
529
529
529
529
1.531e+39
0.5
2.062e+39
0.7
3.593e+39
1.2
43
B1g
547
547
547
547
2.218e+39
0.8
1.663e+39
0.6
3.881e+39
1.3
44
A2u
603
603
603
621
45
B1g
804
804
804
804
1.009e+41
34.2
7.566e+40
25.7
1.765e+41
59.9
46
B2u
826
826
826
826
47
A2u
828
828
828
829
48
A1g
829
829
829
849
2.946e+41
99.9
2.050e+38
0.1
2.948e+41
100.0
49
Eu
849
849
849
849
50
Eu
849
852
852
852
51
Eg
852
852
852
852
1.020e+40
3.5
1.402e+40
4.8
2.422e+40
8.2
52
Eg
852
864
864
853
1.020e+40
3.5
1.402e+40
4.8
2.422e+40
8.2
53
A1g
864
948
948
864
3.512e+40
11.9
6.243e+37
0.0
3.518e+40
11.9
54
A2u
948
984
984
993
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.