- DISTHENE - Al₂SiO₅

Theoretical atomic positions and lattice parameters 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:	2		P-1
Lattice parameters (Å):	7.7930	7.8974		5.5558
Angles (°):	90.0	101.1		106.0

Symmetry (theoretical):

Space group:	2		P-1
Lattice parameters (Å):	7.1262	7.8520		5.5724
Angles (°):	90.0	101.1		106.0

Cell contents:

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

Atomic positions (theoretical):

Al:	0.3254	0.7040	0.4582
Al:	0.2974	0.6989	0.9505
Al:	0.0998	0.3862	0.6403
Al:	0.1120	0.9175	0.1649
Si:	0.2962	0.0649	0.7066
Si:	0.2910	0.3317	0.1892
O:	0.1095	0.1468	0.1288
O:	0.1230	0.6856	0.1812
O:	0.2747	0.4545	0.9547
O:	0.2831	0.9354	0.9353
O:	0.1084	0.1520	0.6669
O:	0.1219	0.6307	0.6389
O:	0.2822	0.4453	0.4288
O:	0.2915	0.9467	0.4659
O:	0.5008	0.2749	0.2440
O:	0.5015	0.2312	0.7553
Al:	0.6746	0.2960	0.5418
Al:	0.7026	0.3011	0.0495
Al:	0.9002	0.6138	0.3597
Al:	0.8880	0.0825	0.8351
Si:	0.7038	0.9351	0.2934
Si:	0.7090	0.6683	0.8108
O:	0.8905	0.8532	0.8712
O:	0.8770	0.3144	0.8188
O:	0.7253	0.5455	0.0453
O:	0.7169	0.0646	0.0647
O:	0.8916	0.8480	0.3331
O:	0.8781	0.3693	0.3611
O:	0.7178	0.5547	0.5712
O:	0.7085	0.0533	0.5341
O:	0.4992	0.7251	0.7560
O:	0.4985	0.7688	0.2447

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	Ag	166	166	166	166	5.376e+37 0.4	5.076e+37 0.4	1.045e+38 0.8
5	Ag	200	200	200	200	1.354e+38 1.1	5.913e+37 0.5	1.945e+38 1.5
6	Ag	216	216	216	216	3.715e+38 2.9	2.153e+37 0.2	3.930e+38 3.1
7	Au	221	222	225	222
8	Au	232	232	232	232
9	Ag	232	232	233	233	1.195e+38 0.9	3.839e+37 0.3	1.579e+38 1.2
10	Ag	241	241	241	241	3.275e+37 0.3	1.608e+37 0.1	4.883e+37 0.4
11	Au	243	243	243	243
12	Au	263	264	264	264
13	Ag	265	265	265	265	4.097e+38 3.2	2.392e+37 0.2	4.336e+38 3.4
14	Ag	275	275	275	275	4.085e+38 3.2	1.388e+37 0.1	4.224e+38 3.3
15	Au	278	278	278	278
16	Ag	278	278	281	278	1.499e+38 1.2	9.874e+37 0.8	2.487e+38 2.0
17	Ag	284	284	284	284	3.603e+39 28.4	6.869e+37 0.5	3.672e+39 29.0
18	Au	293	297	293	294
19	Ag	301	301	301	301	4.379e+38 3.5	2.136e+38 1.7	6.515e+38 5.1
20	Au	302	302	303	306
21	Ag	309	309	309	309	2.583e+39 20.4	1.052e+38 0.8	2.688e+39 21.2
22	Au	313	313	314	317
23	Ag	324	324	324	324	7.234e+37 0.6	7.703e+37 0.6	1.494e+38 1.2
24	Au	327	327	328	328
25	Au	337	337	337	337
26	Ag	341	341	341	341	2.526e+39 19.9	1.317e+38 1.0	2.658e+39 21.0
27	Ag	351	351	351	351	5.709e+38 4.5	4.202e+38 3.3	9.910e+38 7.8
28	Ag	353	353	353	353	4.394e+38 3.5	6.489e+38 5.1	1.088e+39 8.6
29	Au	354	354	354	354
30	Au	360	363	360	360
31	Ag	363	365	363	363	3.922e+39 30.9	1.935e+38 1.5	4.116e+39 32.5
32	Au	367	367	368	368
33	Au	368	371	370	369
34	Ag	374	374	374	374	1.753e+39 13.8	2.813e+37 0.2	1.781e+39 14.1
35	Ag	377	377	377	377	5.788e+39 45.7	2.178e+38 1.7	6.006e+39 47.4
36	Au	383	384	384	384
37	Ag	395	395	395	395	1.792e+38 1.4	2.405e+38 1.9	4.197e+38 3.3
38	Au	397	403	403	397
39	Au	410	411	410	410
40	Ag	412	412	412	412	6.235e+38 4.9	1.267e+38 1.0	7.502e+38 5.9
41	Au	412	415	415	414
42	Ag	415	422	424	415	2.454e+39 19.4	1.433e+38 1.1	2.597e+39 20.5
43	Ag	424	424	424	424	1.801e+39 14.2	8.213e+37 0.6	1.883e+39 14.9
44	Au	426	429	428	430
45	Ag	430	430	430	430	1.870e+38 1.5	1.761e+38 1.4	3.632e+38 2.9
46	Au	430	447	430	451
47	Au	454	455	454	454
48	Ag	455	459	455	455	7.711e+38 6.1	6.919e+37 0.5	8.403e+38 6.6
49	Ag	461	461	461	461	1.263e+40 99.7	4.345e+37 0.3	1.267e+40 100.0
50	Au	464	467	469	469
51	Ag	469	469	470	475	1.485e+39 11.7	8.538e+37 0.7	1.571e+39 12.4
52	Au	475	481	478	483
53	Ag	483	483	483	488	6.634e+38 5.2	2.041e+38 1.6	8.675e+38 6.8
54	Au	489	489	492	495
55	Au	497	497	499	504
56	Au	506	511	512	511
57	Ag	512	512	512	512	3.483e+38 2.7	2.080e+38 1.6	5.563e+38 4.4
58	Au	514	515	515	524
59	Au	527	529	529	528
60	Ag	529	534	534	529	1.962e+39 15.5	3.827e+38 3.0	2.344e+39 18.5
61	Au	534	538	538	538
62	Ag	538	541	549	539	6.563e+38 5.2	4.221e+38 3.3	1.078e+39 8.5
63	Ag	552	552	552	552	4.085e+38 3.2	2.362e+38 1.9	6.446e+38 5.1
64	Au	553	563	562	555
65	Au	564	573	573	573
66	Ag	573	579	575	580	1.233e+39 9.7	1.114e+38 0.9	1.345e+39 10.6
67	Ag	580	580	580	585	4.706e+38 3.7	9.120e+37 0.7	5.618e+38 4.4
68	Au	585	595	595	595
69	Ag	595	602	601	605	3.650e+38 2.9	1.561e+38 1.2	5.212e+38 4.1
70	Au	605	609	609	609
71	Ag	609	621	621	621	9.937e+38 7.8	2.093e+38 1.7	1.203e+39 9.5
72	Ag	621	622	627	624	4.945e+38 3.9	4.738e+38 3.7	9.683e+38 7.6
73	Au	627	630	627	627
74	Ag	631	631	631	631
75	Au	632	645	645	645	7.620e+38 6.0	1.035e+39 8.2	1.797e+39 14.2
76	Ag	645	646	650	647	1.481e+38 1.2	5.014e+37 0.4	1.982e+38 1.6
77	Au	650	661	661	661
78	Ag	661	683	683	679	1.426e+38 1.1	1.024e+38 0.8	2.450e+38 1.9
79	Ag	683	689	683	683	3.916e+38 3.1	1.867e+38 1.5	5.783e+38 4.6
80	Au	689	715	702	702
81	Au	826	828	827	826
82	Au	829	837	837	830
83	Ag	837	843	849	837	5.801e+39 45.8	1.681e+39 13.3	7.482e+39 59.0
84	Ag	849	849	849	849	5.092e+39 40.2	1.648e+39 13.0	6.740e+39 53.2
85	Au	857	859	858	858
86	Ag	864	864	864	864	2.384e+38 1.9	2.836e+38 2.2	5.220e+38 4.1
87	Au	865	882	865	867
88	Ag	886	886	886	886
89	Au	886	894	887	894	3.085e+39 24.3	1.430e+38 1.1	3.228e+39 25.5
90	Au	894	896	896	896
91	Ag	896	899	899	899	9.600e+39 75.7	8.283e+37 0.7	9.683e+39 76.4
92	Ag	899	901	902	909	5.282e+39 41.7	2.824e+39 22.3	8.107e+39 64.0
93	Ag	909	909	909	927	6.506e+39 51.3	1.261e+39 9.9	7.766e+39 61.3
94	Au	928	952	952	952
95	Ag	952	965	962	966	1.280e+39 10.1	5.081e+38 4.0	1.788e+39 14.1
96	Au	970	1006	1039	1015

No.

Char.

ω TO

ω LOx

ω LOy

ω LOz

I ∥

I ⊥