- DISTHENE - Al₂SiO₅

Theoretical atomic positions and lattice parameters at experimental volum 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):	7.1294	7.8444		5.5753
Angles (°):	89.7	101.2		106.0

Cell contents:

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

Atomic positions (theoretical):

Al:	0.3241	0.7039	0.4578
Al:	0.2963	0.6985	0.9500
Al:	0.0999	0.3866	0.6405
Al:	0.1119	0.9170	0.1651
Si:	0.2959	0.0650	0.7066
Si:	0.2908	0.3313	0.1894
O:	0.1119	0.1454	0.1273
O:	0.1240	0.6877	0.1833
O:	0.2719	0.4550	0.9564
O:	0.2801	0.9332	0.9325
O:	0.1104	0.1544	0.6702
O:	0.1235	0.6290	0.6379
O:	0.2791	0.4439	0.4265
O:	0.2883	0.9467	0.4666
O:	0.5025	0.2787	0.2458
O:	0.5033	0.2283	0.7558
Al:	0.6759	0.2961	0.5422
Al:	0.7037	0.3015	0.0500
Al:	0.9001	0.6134	0.3595
Al:	0.8881	0.0830	0.8349
Si:	0.7041	0.9350	0.2934
Si:	0.7092	0.6687	0.8106
O:	0.8881	0.8546	0.8727
O:	0.8760	0.3123	0.8167
O:	0.7281	0.5450	0.0436
O:	0.7199	0.0668	0.0675
O:	0.8896	0.8456	0.3298
O:	0.8765	0.3710	0.3621
O:	0.7209	0.5561	0.5735
O:	0.7117	0.0533	0.5334
O:	0.4975	0.7213	0.7542
O:	0.4967	0.7717	0.2442

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	163	163	163	163	4.194e+37 0.4	3.764e+37 0.3	7.958e+37 0.7
5	Ag	196	196	196	196	1.619e+38 1.4	5.897e+37 0.5	2.208e+38 2.0
6	Ag	215	215	215	215	2.972e+38 2.7	3.601e+37 0.3	3.333e+38 3.0
7	Au	218	218	223	218
8	Ag	230	230	230	230	1.480e+38 1.3	5.670e+37 0.5	2.047e+38 1.8
9	Au	232	232	232	233
10	Ag	239	239	239	239	3.533e+37 0.3	2.051e+37 0.2	5.584e+37 0.5
11	Au	241	242	241	241
12	Au	261	262	263	262
13	Ag	263	263	263	263	7.291e+38 6.5	3.658e+37 0.3	7.656e+38 6.8
14	Ag	274	274	274	274	4.156e+38 3.7	2.076e+37 0.2	4.364e+38 3.9
15	Au	277	277	279	277
16	Ag	279	279	279	279	7.454e+37 0.7	7.444e+37 0.7	1.490e+38 1.3
17	Ag	281	281	281	281	3.289e+39 29.4	7.271e+37 0.6	3.362e+39 30.0
18	Au	291	295	291	292
19	Ag	295	295	295	295	3.936e+38 3.5	2.354e+38 2.1	6.290e+38 5.6
20	Au	300	301	302	304
21	Ag	306	306	306	306	2.135e+39 19.1	1.082e+38 1.0	2.243e+39 20.0
22	Au	311	311	313	317
23	Ag	322	322	322	322	6.401e+37 0.6	7.934e+37 0.7	1.433e+38 1.3
24	Au	327	327	327	328
25	Au	337	338	338	338
26	Ag	339	339	339	339	1.638e+39 14.6	1.109e+38 1.0	1.749e+39 15.6
27	Ag	349	349	349	349	6.685e+38 6.0	4.139e+38 3.7	1.082e+39 9.7
28	Ag	350	350	350	350	5.116e+38 4.6	6.247e+38 5.6	1.136e+39 10.2
29	Au	356	356	356	356
30	Au	358	363	358	358
31	Ag	363	366	363	363	4.151e+39 37.1	1.730e+38 1.5	4.324e+39 38.6
32	Au	367	367	369	368
33	Au	370	371	371	371
34	Ag	376	376	376	376	3.107e+39 27.8	1.077e+38 1.0	3.215e+39 28.7
35	Ag	379	379	379	379	1.745e+39 15.6	1.725e+38 1.5	1.917e+39 17.1
36	Au	384	386	385	386
37	Au	393	395	395	394
38	Ag	395	398	401	395	1.853e+38 1.7	2.388e+38 2.1	4.241e+38 3.8
39	Au	411	411	411	411
40	Ag	411	414	411	412	5.398e+38 4.8	1.742e+38 1.6	7.140e+38 6.4
41	Au	415	416	416	416
42	Ag	416	425	425	416	2.153e+39 19.2	8.231e+37 0.7	2.236e+39 20.0
43	Ag	425	425	426	425	1.953e+39 17.5	4.861e+37 0.4	2.002e+39 17.9
44	Au	428	429	429	429
45	Ag	429	433	430	434	4.433e+38 4.0	1.795e+38 1.6	6.228e+38 5.6
46	Au	434	451	436	454
47	Au	456	459	456	456
48	Ag	459	461	459	459	1.381e+38 1.2	6.495e+37 0.6	2.031e+38 1.8
49	Ag	465	465	465	465	8.596e+39 76.8	2.636e+37 0.2	8.623e+39 77.1
50	Au	467	470	472	472
51	Ag	472	472	474	481	2.865e+39 25.6	7.009e+37 0.6	2.935e+39 26.2
52	Au	482	487	483	493
53	Ag	494	494	494	494	4.086e+38 3.7	2.430e+38 2.2	6.516e+38 5.8
54	Au	495	495	497	500
55	Au	501	501	503	510
56	Au	515	515	515	516
57	Au	516	517	517	517
58	Ag	517	519	523	527	2.227e+38 2.0	1.663e+38 1.5	3.890e+38 3.5
59	Au	534	537	537	534
60	Au	537	540	540	540
61	Ag	540	542	542	542	1.174e+39 10.5	4.125e+38 3.7	1.587e+39 14.2
62	Ag	542	549	555	544	6.638e+38 5.9	3.804e+38 3.4	1.044e+39 9.3
63	Ag	559	559	559	559	3.796e+38 3.4	2.403e+38 2.1	6.199e+38 5.5
64	Au	560	573	569	561
65	Au	573	580	580	580
66	Ag	580	586	580	586	8.478e+38 7.6	1.232e+38 1.1	9.710e+38 8.7
67	Ag	586	591	586	594	2.682e+38 2.4	8.581e+37 0.8	3.540e+38 3.2
68	Au	595	600	600	600
69	Ag	600	606	607	613	1.831e+38 1.6	1.432e+38 1.3	3.263e+38 2.9
70	Ag	613	613	613	613
71	Au	613	623	626	626	1.193e+39 10.7	1.857e+38 1.7	1.379e+39 12.3
72	Ag	626	626	628	628	6.061e+38 5.4	7.774e+38 6.9	1.383e+39 12.4
73	Au	628	637	637	637
74	Ag	637	639	638	638	6.047e+38 5.4	5.593e+38 5.0	1.164e+39 10.4
75	Au	645	654	654	654
76	Ag	654	655	660	654	8.775e+37 0.8	2.993e+37 0.3	1.177e+38 1.1
77	Au	660	672	672	672
78	Ag	672	698	698	693	4.615e+38 4.1	1.253e+38 1.1	5.868e+38 5.2
79	Ag	698	703	698	698	3.086e+38 2.8	1.000e+38 0.9	4.086e+38 3.7
80	Au	704	725	717	714
81	Au	837	838	837	837
82	Au	841	849	849	841
83	Ag	849	855	858	849	6.578e+39 58.8	1.509e+39 13.5	8.086e+39 72.3
84	Ag	858	858	861	858	4.093e+39 36.6	1.667e+39 14.9	5.760e+39 51.5
85	Au	867	869	871	869
86	Au	875	877	876	877
87	Ag	877	896	877	878	1.478e+38 1.3	1.292e+38 1.2	2.770e+38 2.5
88	Ag	900	900	900	900	2.677e+39 23.9	1.161e+38 1.0	2.794e+39 25.0
89	Au	900	907	902	907
90	Ag	907	908	907	909	5.876e+39 52.5	4.091e+38 3.7	6.285e+39 56.2
91	Au	909	912	912	912
92	Ag	912	913	917	923	8.744e+39 78.1	2.446e+39 21.9	1.119e+40 100.0
93	Ag	923	923	923	941	6.841e+39 61.1	1.431e+39 12.8	8.272e+39 73.9
94	Au	942	964	964	964
95	Ag	964	978	975	978	1.410e+39 12.6	5.266e+38 4.7	1.937e+39 17.3
96	Au	983	1017	1052	1027

No.

Char.

ω TO

ω LOx

ω LOy

ω LOz

I ∥

I ⊥