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

OLIGOCLASE - 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):  7.5984  7.5262  7.0384 
Angles (°):  105.9  101.9  115.0 

Cell contents: 

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

Atomic positions (theoretical):

Na:  0.2601  0.2729  0.1293 
Si:  0.8408  0.1755  0.2178 
Si:  0.1885  0.8223  0.2274 
Si:  0.5790  0.7992  0.3242 
Si:  0.8066  0.5640  0.3485 
O:  0.8709  0.1356  0.9883 
O:  0.5981  0.5832  0.2777 
O:  0.7092  0.9333  0.2043 
O:  0.9662  0.6722  0.2384 
O:  0.7222  0.3080  0.2677 
O:  0.3297  0.7085  0.2214 
O:  0.0807  0.3106  0.3918 
O:  0.3216  0.0598  0.4211 
Na:  0.7399  0.7271  0.8707 
Si:  0.1592  0.8245  0.7822 
Si:  0.8115  0.1777  0.7726 
Si:  0.4210  0.2008  0.6758 
Si:  0.1934  0.4360  0.6515 
O:  0.1291  0.8644  0.0117 
O:  0.4019  0.4168  0.7223 
O:  0.2908  0.0667  0.7957 
O:  0.0338  0.3278  0.7616 
O:  0.2778  0.6920  0.7323 
O:  0.6703  0.2915  0.7786 
O:  0.9193  0.6894  0.6082 
O:  0.6784  0.9402  0.5789 
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
40
40
40
40
4.694e+38
1.4
2.308e+38
0.7
7.002e+38
2.1
5
Au
59
65
66
66
6
Ag
66
66
75
69
1.016e+39
3.0
8.807e+38
2.6
1.897e+39
5.6
7
Ag
86
86
86
86
7.612e+38
2.2
3.421e+38
1.0
1.103e+39
3.2
8
Au
89
90
95
94
9
Ag
106
106
106
106
7.334e+38
2.1
1.035e+39
3.0
1.768e+39
5.2
10
Ag
132
132
132
132
5.027e+38
1.5
3.726e+38
1.1
8.754e+38
2.6
11
Au
146
146
148
149
12
Ag
157
157
157
157
13
Au
157
158
160
160
6.396e+38
1.9
3.812e+38
1.1
1.021e+39
3.0
14
Ag
163
163
163
163
8.969e+38
2.6
1.096e+39
3.2
1.993e+39
5.8
15
Ag
173
173
173
173
1.259e+39
3.7
1.137e+39
3.3
2.396e+39
7.0
16
Ag
184
184
184
184
8.892e+39
26.1
4.015e+38
1.2
9.294e+39
27.2
17
Au
195
195
199
198
18
Ag
206
206
206
206
5.458e+38
1.6
4.432e+38
1.3
9.890e+38
2.9
19
Au
211
216
211
213
20
Au
217
221
217
217
21
Ag
221
223
221
221
3.469e+38
1.0
2.023e+38
0.6
5.491e+38
1.6
22
Au
250
250
250
250
23
Ag
258
258
258
258
3.484e+38
1.0
1.029e+38
0.3
4.512e+38
1.3
24
Au
263
263
263
263
25
Au
270
270
270
270
26
Ag
272
272
272
272
2.612e+39
7.7
1.064e+38
0.3
2.719e+39
8.0
27
Ag
279
279
279
279
9.185e+39
26.9
4.418e+38
1.3
9.627e+39
28.2
28
Ag
301
301
301
301
1.791e+38
0.5
7.606e+37
0.2
2.551e+38
0.7
29
Au
308
308
309
308
30
Au
319
321
320
319
31
Ag
333
333
333
333
2.760e+38
0.8
1.072e+38
0.3
3.832e+38
1.1
32
Au
335
335
348
335
33
Ag
356
356
356
356
3.722e+38
1.1
3.714e+38
1.1
7.436e+38
2.2
34
Au
371
372
372
372
35
Au
376
377
377
380
36
Au
381
382
382
382
37
Ag
382
389
383
394
7.531e+38
2.2
1.926e+38
0.6
9.457e+38
2.8
38
Au
394
395
395
395
39
Ag
395
398
398
398
6.119e+38
1.8
1.177e+38
0.3
7.295e+38
2.1
40
Ag
398
402
404
406
6.234e+38
1.8
3.645e+37
0.1
6.598e+38
1.9
41
Au
406
408
428
426
42
Au
445
450
445
446
43
Ag
453
453
453
453
2.607e+38
0.8
2.297e+38
0.7
4.904e+38
1.4
44
Au
456
456
456
456
45
Ag
465
465
465
465
5.225e+39
15.3
1.190e+38
0.3
5.344e+39
15.7
46
Ag
466
466
466
466
4.468e+39
13.1
1.072e+38
0.3
4.575e+39
13.4
47
Ag
499
499
499
499
3.406e+40
99.8
6.338e+37
0.2
3.412e+40
100.0
48
Au
536
536
550
536
49
Au
570
573
571
573
50
Ag
573
594
573
591
2.574e+39
7.5
2.213e+37
0.1
2.596e+39
7.6
51
Au
610
610
612
611
52
Au
640
644
641
644
53
Ag
644
650
644
646
6.931e+38
2.0
3.580e+37
0.1
7.289e+38
2.1
54
Ag
650
656
650
650
1.059e+38
0.3
1.180e+38
0.3
2.239e+38
0.7
55
Au
740
740
740
740
56
Au
745
746
746
747
57
Ag
754
754
754
754
2.416e+39
7.1
2.899e+38
0.8
2.706e+39
7.9
58
Ag
762
762
762
762
4.536e+38
1.3
6.352e+38
1.9
1.089e+39
3.2
59
Au
769
769
774
770
60
Ag
787
787
787
787
1.375e+39
4.0
2.060e+38
0.6
1.581e+39
4.6
61
Au
789
798
790
789
62
Ag
810
810
810
810
1.219e+39
3.6
4.274e+38
1.3
1.646e+39
4.8
63
Au
959
959
962
962
64
Ag
962
962
970
963
6.531e+38
1.9
8.176e+38
2.4
1.471e+39
4.3
65
Ag
970
970
972
970
3.817e+38
1.1
4.578e+38
1.3
8.395e+38
2.5
66
Au
976
978
998
998
67
Ag
998
998
1004
1004
7.909e+37
0.2
8.194e+37
0.2
1.610e+38
0.5
68
Au
1004
1014
1014
1014
69
Ag
1014
1019
1025
1020
5.172e+38
1.5
4.109e+38
1.2
9.281e+38
2.7
70
Au
1025
1037
1037
1037
71
Ag
1037
1049
1041
1058
1.159e+38
0.3
7.529e+37
0.2
1.912e+38
0.6
72
Ag
1064
1064
1064
1064
1.422e+38
0.4
1.621e+38
0.5
3.043e+38
0.9
73
Au
1072
1072
1074
1075
74
Au
1075
1076
1086
1076
75
Ag
1086
1086
1096
1086
3.628e+38
1.1
2.747e+38
0.8
6.374e+38
1.9
76
Au
1096
1114
1112
1109
77
Ag
1115
1115
1115
1115
2.310e+38
0.7
2.575e+38
0.8
4.885e+38
1.4
78
Au
1117
1182
1139
1156
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.