-    KALSILITE     -    KAlSiO4

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 RRUFF, entry #R060801 

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:  173  P6_3 
Lattice parameters (Å):  5.1520  5.1520  8.6621 
Angles (°):  90.0  90.0  120.0 

Symmetry (theoretical): 

Space group:  173  P6_3 
Lattice parameters (Å):  4.9357  4.9365  8.5724 
Angles (°):  90.0  90.0  120.0 

Cell contents: 

Number of atoms:  14 
Number of atom types: 
Chemical composition: 

Atomic positions (theoretical):

K:  0.9999  0.0001  0.2489 
Al:  0.3332  0.6666  0.0551 
Si:  0.3335  0.6669  0.4389 
O:  0.3332  0.6667  0.2528 
O:  0.6467  0.0141  0.9967 
K:  0.0001  0.9999  0.7489 
Al:  0.6668  0.3334  0.5551 
Si:  0.6665  0.3331  0.9389 
O:  0.6668  0.3333  0.7528 
O:  0.6327  0.6469  0.4966 
O:  0.9851  0.6320  0.9969 
O:  0.3533  0.9859  0.4967 
O:  0.3673  0.3531  0.9966 
O:  0.0149  0.3680  0.4969 
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
B
32
32
36
32
1.166e+39
2.2
1.954e+39
3.6
3.121e+39
5.8
5
B
36
44
41
36
1.033e+39
1.9
1.110e+39
2.1
2.142e+39
4.0
6
A
48
48
48
48
4.924e+38
0.9
5.866e+38
1.1
1.079e+39
2.0
7
A
49
49
49
49
4.908e+38
0.9
4.574e+38
0.9
9.482e+38
1.8
8
A
115
115
115
115
7.151e+36
0.0
5.363e+36
0.0
1.251e+37
0.0
9
A
115
115
115
115
8.134e+36
0.0
1.006e+37
0.0
1.819e+37
0.0
10
A
117
117
117
136
4.333e+37
0.1
1.892e+36
0.0
4.522e+37
0.1
11
B
136
136
136
137
4.207e+36
0.0
5.785e+36
0.0
9.992e+36
0.0
12
B
137
137
137
137
9.176e+37
0.2
1.138e+38
0.2
2.055e+38
0.4
13
B
137
161
161
145
9.437e+37
0.2
1.404e+38
0.3
2.348e+38
0.4
14
A
216
216
216
216
1.363e+38
0.3
1.098e+38
0.2
2.461e+38
0.5
15
A
216
216
216
216
1.385e+38
0.3
1.822e+38
0.3
3.208e+38
0.6
16
B
289
289
289
289
17
A
310
310
310
310
1.972e+38
0.4
1.552e+38
0.3
3.525e+38
0.7
18
A
310
310
310
310
1.962e+38
0.4
2.622e+38
0.5
4.584e+38
0.9
19
B
346
346
346
346
20
B
369
369
369
369
8.968e+37
0.2
1.182e+38
0.2
2.079e+38
0.4
21
B
369
379
379
369
8.762e+37
0.2
1.259e+38
0.2
2.135e+38
0.4
22
A
392
392
392
400
5.293e+40
98.7
7.203e+38
1.3
5.365e+40
100.0
23
A
441
441
441
446
2.025e+40
37.7
1.216e+39
2.3
2.146e+40
40.0
24
B
446
446
446
446
6.971e+38
1.3
8.727e+38
1.6
1.570e+39
2.9
25
B
446
455
455
455
6.904e+38
1.3
1.034e+39
1.9
1.725e+39
3.2
26
A
455
455
455
455
2.480e+38
0.5
2.497e+38
0.5
4.977e+38
0.9
27
A
455
479
479
481
2.454e+38
0.5
2.752e+38
0.5
5.206e+38
1.0
28
B
481
481
481
501
29
B
625
625
625
625
30
A
655
655
655
657
9.221e+38
1.7
1.483e+38
0.3
1.070e+39
2.0
31
B
702
702
703
702
2.526e+37
0.0
2.699e+37
0.1
5.225e+37
0.1
32
A
703
703
703
703
2.414e+37
0.0
4.055e+37
0.1
6.469e+37
0.1
33
B
703
704
704
703
2.672e+38
0.5
3.633e+38
0.7
6.305e+38
1.2
34
A
704
733
731
704
2.740e+38
0.5
2.091e+38
0.4
4.831e+38
0.9
35
A
945
945
945
971
7.311e+39
13.6
1.772e+38
0.3
7.488e+39
14.0
36
A
976
976
976
976
1.916e+38
0.4
2.148e+38
0.4
4.064e+38
0.8
37
B
976
977
977
976
1.413e+39
2.6
1.246e+39
2.3
2.660e+39
5.0
38
A
978
978
978
978
1.904e+38
0.4
3.100e+38
0.6
5.004e+38
0.9
39
B
978
997
997
978
1.415e+39
2.6
1.747e+39
3.3
3.161e+39
5.9
40
B
997
1060
1060
997
7.121e+35
0.0
9.792e+35
0.0
1.691e+36
0.0
41
A
1060
1088
1089
1147
2.368e+39
4.4
1.073e+38
0.2
2.475e+39
4.6
42
B
1147
1147
1147
1159
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.