-    PLAGIOCLASE     -    (Na,Ca)(Si,Al)4O8

ANDESINE - Theoretical structure, term in the plagioclase series treated as ideal solid solution using alchemical pseudopotentials. 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:  2  P-1 
Lattice parameters (Å):  7.599  7.533  6.081 
Angles (°):  106.12  101.66  114.92 

Symmetry (theoretical): 

Space group:  2  P-1 
Lattice parameters (Å):  7.6269  7.5268  7.0355 
Angles (°):  105.7  101.9  114.7 

Cell contents: 

Number of atoms:  26 
Number of atom types:  3 
Chemical composition:  0 

Atomic positions (theoretical):

Na:  0.2569  0.2747  0.1231 
Si:  0.8379  0.1753  0.2197 
Si:  0.1877  0.8238  0.2274 
Si:  0.5738  0.7990  0.3272 
Si:  0.8072  0.5691  0.3496 
O:  0.8686  0.1323  0.9896 
O:  0.5956  0.5840  0.2800 
O:  0.7010  0.9331  0.2046 
O:  0.9613  0.6809  0.2352 
O:  0.7259  0.3142  0.2699 
O:  0.3232  0.7031  0.2241 
O:  0.0783  0.3043  0.3909 
O:  0.3260  0.0617  0.4181 
Na:  0.7431  0.7253  0.8769 
Si:  0.1621  0.8247  0.7803 
Si:  0.8123  0.1762  0.7726 
Si:  0.4262  0.2010  0.6728 
Si:  0.1928  0.4309  0.6504 
O:  0.1314  0.8677  0.0104 
O:  0.4044  0.4160  0.7200 
O:  0.2990  0.0669  0.7954 
O:  0.0387  0.3191  0.7648 
O:  0.2741  0.6858  0.7301 
O:  0.6768  0.2969  0.7759 
O:  0.9217  0.6957  0.6091 
O:  0.6740  0.9383  0.5819 
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
Ag
49
49
49
49
3.862e+38
1.1
2.299e+38
0.7
6.160e+38
1.8
5
Ag
65
65
65
65
6
Au
65
71
79
75
1.080e+39
3.1
1.085e+39
3.1
2.165e+39
6.3
7
Ag
90
90
90
90
1.089e+39
3.2
2.716e+38
0.8
1.361e+39
3.9
8
Au
96
98
103
104
9
Ag
108
108
108
108
5.264e+38
1.5
7.789e+38
2.3
1.305e+39
3.8
10
Ag
133
133
133
133
5.763e+38
1.7
3.740e+38
1.1
9.504e+38
2.8
11
Au
145
145
148
148
12
Au
156
157
157
157
13
Ag
157
157
160
158
5.159e+38
1.5
5.214e+38
1.5
1.037e+39
3.0
14
Ag
163
163
163
163
8.347e+38
2.4
7.485e+38
2.2
1.583e+39
4.6
15
Ag
176
176
176
176
1.367e+39
4.0
1.136e+39
3.3
2.504e+39
7.3
16
Ag
186
186
186
186
7.807e+39
22.7
3.901e+38
1.1
8.197e+39
23.8
17
Au
197
198
202
202
18
Ag
208
208
208
208
4.486e+38
1.3
4.204e+38
1.2
8.690e+38
2.5
19
Au
213
216
214
215
20
Au
220
226
220
220
21
Ag
226
228
226
226
1.679e+38
0.5
2.182e+38
0.6
3.861e+38
1.1
22
Au
246
247
246
247
23
Ag
257
257
257
257
4.908e+37
0.1
4.825e+37
0.1
9.734e+37
0.3
24
Au
270
271
271
270
25
Au
271
271
271
271
26
Ag
275
275
275
275
9.743e+39
28.3
3.970e+38
1.2
1.014e+40
29.4
27
Ag
283
283
283
283
1.433e+39
4.2
9.892e+37
0.3
1.532e+39
4.4
28
Ag
303
303
303
303
9.164e+37
0.3
9.397e+37
0.3
1.856e+38
0.5
29
Au
306
306
307
306
30
Au
323
324
324
323
31
Ag
331
331
331
331
2.364e+38
0.7
7.510e+37
0.2
3.115e+38
0.9
32
Au
336
336
348
336
33
Ag
358
358
358
358
3.135e+38
0.9
3.644e+38
1.1
6.780e+38
2.0
34
Au
373
373
373
373
35
Au
374
375
375
381
36
Au
381
382
382
382
37
Ag
382
388
384
391
7.754e+38
2.2
2.242e+38
0.7
9.996e+38
2.9
38
Au
391
394
394
394
39
Ag
394
399
400
400
5.581e+38
1.6
7.606e+37
0.2
6.341e+38
1.8
40
Ag
400
400
404
403
4.449e+38
1.3
3.698e+37
0.1
4.819e+38
1.4
41
Au
404
406
423
422
42
Au
450
451
450
450
43
Ag
451
452
451
451
3.092e+38
0.9
1.850e+38
0.5
4.942e+38
1.4
44
Au
455
456
455
455
45
Ag
466
466
466
466
3.226e+39
9.4
1.288e+38
0.4
3.355e+39
9.7
46
Ag
467
467
467
467
5.820e+39
16.9
1.109e+38
0.3
5.931e+39
17.2
47
Ag
500
500
500
500
3.440e+40
99.8
6.785e+37
0.2
3.447e+40
100.0
48
Au
533
533
548
533
49
Ag
567
567
567
567
1.535e+39
4.5
1.724e+37
0.1
1.552e+39
4.5
50
Au
569
592
569
588
51
Au
599
599
602
603
52
Au
635
637
636
637
53
Ag
637
641
637
640
4.829e+38
1.4
3.654e+37
0.1
5.194e+38
1.5
54
Ag
641
654
641
641
1.484e+38
0.4
1.074e+38
0.3
2.558e+38
0.7
55
Au
734
734
734
734
56
Au
738
739
739
740
57
Ag
746
746
746
746
2.596e+39
7.5
2.728e+38
0.8
2.869e+39
8.3
58
Ag
757
757
757
757
4.854e+38
1.4
6.612e+38
1.9
1.147e+39
3.3
59
Au
761
761
766
762
60
Ag
782
782
782
782
1.312e+39
3.8
1.916e+38
0.6
1.504e+39
4.4
61
Au
783
792
783
783
62
Ag
802
802
802
802
1.236e+39
3.6
4.322e+38
1.3
1.669e+39
4.8
63
Au
944
945
947
947
64
Ag
947
947
955
949
6.712e+38
1.9
8.479e+38
2.5
1.519e+39
4.4
65
Ag
955
955
956
955
3.632e+38
1.1
4.570e+38
1.3
8.202e+38
2.4
66
Au
960
964
989
989
67
Ag
989
989
996
996
1.246e+38
0.4
9.005e+37
0.3
2.147e+38
0.6
68
Au
996
1001
1001
1001
69
Ag
1001
1008
1013
1007
4.579e+38
1.3
4.043e+38
1.2
8.621e+38
2.5
70
Au
1013
1031
1028
1031
71
Ag
1031
1033
1031
1041
1.176e+38
0.3
7.174e+37
0.2
1.893e+38
0.5
72
Ag
1055
1055
1055
1055
2.222e+38
0.6
2.156e+38
0.6
4.377e+38
1.3
73
Au
1063
1063
1063
1063
74
Au
1067
1072
1073
1073
75
Ag
1073
1073
1079
1074
4.068e+38
1.2
3.083e+38
0.9
7.151e+38
2.1
76
Au
1083
1095
1095
1087
77
Ag
1095
1098
1095
1095
2.491e+38
0.7
2.915e+38
0.8
5.407e+38
1.6
78
Au
1098
1163
1130
1141
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.