- ANDALUSITE - Al₂SiO₅

Experimental structure 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:	58		Pnnm
Lattice parameters (Å):	7.7930	7.8974		5.5558
Angles (°):	90.0	90.0		90.0

Symmetry (theoretical):

Space group:	58		Pnnm
Lattice parameters (Å):	7.7930	7.8974		5.5558
Angles (°):	90.0	90.0		90.0

Cell contents:

Number of atoms:	32
Number of atom types:	3
Chemical composition:	0

Atomic positions (theoretical):

Al:	0.0000	0.0000	0.2419
Al:	0.3716	0.1395	0.5000
Si:	0.2449	0.2541	0.0000
O:	0.4277	0.3626	0.5000
O:	0.4210	0.3674	0.0000
O:	0.1019	0.4013	0.0000
O:	0.2319	0.1368	0.2406
Al:	0.6284	0.8605	0.5000
Si:	0.7551	0.7459	0.0000
O:	0.5723	0.6374	0.5000
O:	0.5790	0.6326	0.0000
O:	0.8981	0.5987	0.0000
O:	0.7681	0.8632	0.2406
Al:	0.5000	0.5000	0.2581
Al:	0.1284	0.6395	0.0000
Si:	0.2551	0.7541	0.5000
O:	0.0723	0.8626	0.0000
O:	0.0790	0.8674	0.5000
O:	0.3981	0.9013	0.5000
O:	0.2681	0.6368	0.2594
Al:	0.8716	0.3605	0.0000
Si:	0.7449	0.2459	0.5000
O:	0.9277	0.1374	0.0000
O:	0.9210	0.1326	0.5000
O:	0.6019	0.0987	0.5000
O:	0.7319	0.3632	0.2594
Al:	0.0000	0.0000	0.7581
O:	0.7681	0.8632	0.7594
O:	0.2319	0.1368	0.7594
Al:	0.5000	0.5000	0.7419
O:	0.7319	0.3632	0.7406
O:	0.2681	0.6368	0.7406

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:

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	B3g	126	126	126	126
5	B2g	151	151	151	151	3.780e+37 0.2	5.197e+37 0.3	8.977e+37 0.4
6	B3g	160	160	160	160	1.986e+36 0.0	2.731e+36 0.0	4.717e+36 0.0
7	B1u	177	177	177	177
8	B2u	182	182	185	182
9	B3u	185	185	185	185
10	B2g	185	199	186	185	3.242e+37 0.2	4.458e+37 0.2	7.700e+37 0.4
11	B3g	205	205	205	205	8.700e+37 0.4	1.196e+38 0.6	2.066e+38 1.0
12	Au	214	214	214	214
13	Au	215	215	215	215
14	B2u	232	232	232	232
15	A1g	236	236	236	236	3.451e+38 1.7	1.561e+38 0.8	5.013e+38 2.4
16	B3u	241	241	241	241
17	B2g	249	249	249	249	6.714e+36 0.0	9.232e+36 0.0	1.595e+37 0.1
18	B3u	274	278	274	274
19	B1g	278	280	278	278	7.311e+37 0.4	1.005e+38 0.5	1.736e+38 0.8
20	B1u	280	282	280	281
21	A1g	282	288	282	282	1.103e+40 53.4	9.647e+37 0.5	1.113e+40 53.9
22	Au	288	292	288	288
23	B2g	292	295	292	292	8.339e+36 0.0	1.147e+37 0.1	1.981e+37 0.1
24	B2u	295	297	297	295
25	B1g	297	304	300	297	6.680e+37 0.3	9.185e+37 0.4	1.586e+38 0.8
26	B3g	317	317	317	317	2.368e+38 1.1	3.256e+38 1.6	5.624e+38 2.7
27	A1g	318	318	318	318	9.109e+39 44.1	4.782e+37 0.2	9.157e+39 44.3
28	B1g	327	327	327	327	4.330e+38 2.1	5.954e+38 2.9	1.028e+39 5.0
29	B3u	336	337	336	336
30	B2u	337	337	341	337
31	Au	341	341	349	341
32	B1u	349	349	349	349
33	A1g	352	352	352	352	7.043e+39 34.1	1.362e+38 0.7	7.179e+39 34.7
34	B1g	352	352	352	352
35	A1g	363	363	363	363	2.252e+37 0.1	1.489e+37 0.1	3.741e+37 0.2
36	B3g	365	365	365	365	2.216e+37 0.1	3.046e+37 0.1	5.262e+37 0.3
37	B3u	371	378	371	371
38	B2g	380	380	380	380	6.370e+37 0.3	8.758e+37 0.4	1.513e+38 0.7
39	B1g	383	383	383	383	1.223e+37 0.1	1.681e+37 0.1	2.904e+37 0.1
40	B2g	383	383	383	383	1.169e+38 0.6	1.607e+38 0.8	2.776e+38 1.3
41	B3g	389	389	389	389	7.699e+38 3.7	1.059e+39 5.1	1.828e+39 8.8
42	B2u	390	390	390	390
43	B2u	404	404	418	404
44	B3u	418	439	439	418
45	A1g	439	442	442	439	5.296e+38 2.6	3.278e+38 1.6	8.574e+38 4.1
46	Au	442	443	443	442
47	B1u	443	453	453	449
48	B2g	453	458	455	453	5.401e+38 2.6	7.426e+38 3.6	1.283e+39 6.2
49	B1g	458	459	458	458	9.123e+37 0.4	1.254e+38 0.6	2.167e+38 1.0
50	B3g	459	483	459	459	5.248e+37 0.3	7.216e+37 0.3	1.246e+38 0.6
51	B3u	489	495	489	489
52	B2u	495	509	503	495
53	Au	509	515	509	509
54	A1g	515	522	515	515	1.736e+39 8.4	1.120e+38 0.5	1.848e+39 8.9
55	B1g	522	524	522	522	1.683e+38 0.8	2.315e+38 1.1	3.998e+38 1.9
56	B3u	525	526	525	525
57	B1u	526	533	526	535
58	B2u	535	535	535	537
59	Au	537	537	537	549
60	A1g	549	549	549	554	3.479e+38 1.7	8.349e+37 0.4	4.314e+38 2.1
61	B3g	554	554	554	557	2.884e+37 0.1	3.966e+37 0.2	6.851e+37 0.3
62	B1u	557	557	557	566
63	B2g	566	566	566	570	1.141e+36 0.0	1.569e+36 0.0	2.711e+36 0.0
64	B3u	570	570	570	570
65	B1g	570	570	570	588	1.280e+38 0.6	1.760e+38 0.9	3.040e+38 1.5
66	B2u	588	588	590	590
67	A1g	590	590	605	605	2.421e+38 1.2	5.429e+37 0.3	2.964e+38 1.4
68	B2g	605	605	617	617	3.903e+37 0.2	5.367e+37 0.3	9.271e+37 0.4
69	B1g	617	617	617	624	4.369e+37 0.2	6.008e+37 0.3	1.038e+38 0.5
70	B2u	624	624	625	625
71	B3g	625	625	628	626	3.141e+38 1.5	4.319e+38 2.1	7.461e+38 3.6
72	B1u	628	628	652	652
73	Au	652	652	680	662
74	A1g	680	680	683	680	1.855e+39 9.0	9.572e+37 0.5	1.950e+39 9.4
75	B1g	683	683	687	683	2.972e+38 1.4	4.087e+38 2.0	7.059e+38 3.4
76	B3u	687	699	712	687
77	B3u	724	736	724	724
78	B2u	746	746	746	746
79	A1g	773	773	773	773	2.688e+38 1.3	1.716e+38 0.8	4.404e+38 2.1
80	B1g	773	773	773	773	3.400e+37 0.2	4.676e+37 0.2	8.076e+37 0.4
81	B3u	812	824	812	812
82	B2u	824	861	824	824
83	B2u	861	861	863	861
84	B3u	864	867	864	864
85	A1g	867	883	867	867	2.061e+40 99.7	5.713e+37 0.3	2.066e+40 100.0
86	B1u	883	884	883	884
87	B3g	884	892	884	892	2.468e+39 11.9	3.394e+39 16.4	5.862e+39 28.4
88	B1g	892	894	892	894	2.612e+38 1.3	3.591e+38 1.7	6.203e+38 3.0
89	Au	894	894	894	894
90	B2g	894	904	894	904	2.180e+38 1.1	2.997e+38 1.5	5.177e+38 2.5
91	A1g	904	908	904	908	3.427e+39 16.6	1.096e+39 5.3	4.524e+39 21.9
92	B2u	908	918	918	918
93	B3u	918	961	976	976
94	B1g	976	976	1003	1003	1.618e+39 7.8	2.225e+39 10.8	3.843e+39 18.6
95	A1g	1003	1003	1029	1017	4.179e+39 20.2	3.232e+38 1.6	4.502e+39 21.8
96	B1g	1049	1049	1049	1049	6.982e+38 3.4	9.600e+38 4.6	1.658e+39 8.0

No.

Char.

ω TO

ω LOx

ω LOy

ω LOz

I ∥

I ⊥