- IIMORIITE - Y₂SiO₄CO₃

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):	6.5495	6.6291		6.4395
Angles (°):	116.364	92.556		95.506

Symmetry (theoretical):

Space group:	2		P-1
Lattice parameters (Å):	6.3302	6.3285		6.1895
Angles (°):	115.74	93.21		96.17

Cell contents:

Number of atoms:	22
Number of atom types:	4
Chemical composition:	0

Atomic positions (theoretical):

Y:	0.1793	0.1796	0.2481
Y:	0.4173	0.6980	0.2536
Si:	0.6624	0.2427	0.2647
C:	0.9117	0.7318	0.1966
O:	0.1061	0.8351	0.2686
O:	0.5278	0.3381	0.1059
O:	0.4845	0.0824	0.3357
O:	0.1589	0.9075	0.8700
O:	0.2186	0.2503	0.6502
O:	0.1497	0.3830	0.0277
O:	0.2541	0.5520	0.4706
Y:	0.8207	0.8204	0.7519
Y:	0.5827	0.3020	0.7464
Si:	0.3376	0.7573	0.7353
C:	0.0883	0.2682	0.8034
O:	0.8939	0.1649	0.7314
O:	0.4722	0.6619	0.8941
O:	0.5155	0.9176	0.6643
O:	0.8411	0.0925	0.1300
O:	0.7814	0.7497	0.3498
O:	0.8503	0.6170	0.9723
O:	0.7459	0.4480	0.5294

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	94	94	94	94	1.868e+39 3.1	1.927e+39 3.2	3.795e+39 6.2
5	Au	105	120	106	106
6	Ag	136	136	136	136	2.478e+39 4.1	2.712e+39 4.5	5.190e+39 8.5
7	Ag	148	148	148	148	3.589e+38 0.6	4.517e+38 0.7	8.106e+38 1.3
8	Au	175	177	176	175
9	Au	189	192	189	192
10	Ag	193	193	193	193	6.374e+38 1.0	4.829e+38 0.8	1.120e+39 1.8
11	Ag	200	200	200	200	3.537e+39 5.8	7.892e+38 1.3	4.326e+39 7.1
12	Ag	210	210	210	210	2.350e+39 3.9	2.520e+39 4.1	4.870e+39 8.0
13	Au	228	228	229	229
14	Ag	229	229	230	235	1.612e+39 2.7	1.346e+39 2.2	2.959e+39 4.9
15	Ag	238	238	238	238	4.601e+39 7.6	4.271e+39 7.0	8.873e+39 14.6
16	Au	245	245	245	250
17	Au	258	264	258	258
18	Ag	264	264	264	264	4.922e+39 8.1	3.051e+39 5.0	7.973e+39 13.1
19	Au	272	285	279	272
20	Ag	285	285	285	285	3.634e+39 6.0	5.158e+39 8.5	8.791e+39 14.5
21	Au	287	293	293	292
22	Ag	293	296	305	293	5.840e+39 9.6	4.672e+39 7.7	1.051e+40 17.3
23	Ag	305	305	310	305	3.956e+39 6.5	4.139e+39 6.8	8.094e+39 13.3
24	Au	313	313	329	317
25	Au	334	336	334	334
26	Ag	336	355	336	336	3.286e+39 5.4	3.081e+39 5.1	6.367e+39 10.5
27	Au	355	361	358	369
28	Ag	369	369	369	371	6.434e+39 10.6	4.167e+39 6.9	1.060e+40 17.4
29	Au	371	376	379	388
30	Ag	388	388	388	396	1.484e+40 24.4	1.489e+40 24.5	2.973e+40 48.9
31	Ag	405	405	405	405	4.151e+39 6.8	2.932e+39 4.8	7.083e+39 11.6
32	Au	408	412	409	416
33	Au	417	419	421	421
34	Ag	421	421	425	427	6.493e+39 10.7	6.057e+39 10.0	1.255e+40 20.6
35	Ag	427	427	427	429	7.216e+39 11.9	6.606e+39 10.9	1.382e+40 22.7
36	Au	430	447	433	438
37	Ag	453	453	453	453	8.010e+39 13.2	7.386e+39 12.1	1.540e+40 25.3
38	Au	471	473	481	471
39	Ag	481	481	481	481	5.429e+39 8.9	5.180e+39 8.5	1.061e+40 17.4
40	Au	505	505	506	508
41	Au	544	566	546	548
42	Ag	574	574	574	574	2.398e+39 3.9	2.237e+39 3.7	4.636e+39 7.6
43	Au	575	584	584	580
44	Ag	584	586	590	584	2.035e+39 3.3	8.332e+38 1.4	2.868e+39 4.7
45	Au	608	608	623	623
46	Ag	623	623	625	633	1.307e+39 2.1	1.564e+39 2.6	2.871e+39 4.7
47	Au	698	699	699	698
48	Ag	707	707	707	707	1.232e+39 2.0	1.692e+39 2.8	2.923e+39 4.8
49	Ag	737	737	737	737	2.615e+39 4.3	1.241e+39 2.0	3.856e+39 6.3
50	Au	738	738	739	738
51	Au	824	826	831	824
52	Ag	832	832	832	832	6.639e+39 10.9	4.617e+39 7.6	1.126e+40 18.5
53	Au	853	867	870	853
54	Ag	870	870	878	870	8.574e+39 14.1	7.399e+38 1.2	9.314e+39 15.3
55	Au	899	900	914	907
56	Ag	914	914	929	914	2.858e+40 47.0	1.397e+39 2.3	2.998e+40 49.3
57	Au	961	978	968	964
58	Ag	978	983	978	978	8.225e+39 13.5	4.148e+39 6.8	1.237e+40 20.3
59	Au	989	1016	1016	1016
60	Ag	1016	1019	1016	1043	7.139e+39 11.7	5.267e+39 8.7	1.241e+40 20.4
61	Au	1121	1122	1121	1122
62	Ag	1126	1126	1126	1126	6.036e+40 99.3	4.438e+38 0.7	6.081e+40 100.0
63	Ag	1416	1416	1416	1416	6.300e+39 10.4	5.028e+39 8.3	1.133e+40 18.6
64	Au	1469	1480	1473	1474
65	Au	1488	1501	1493	1501
66	Ag	1501	1546	1501	1555	4.151e+39 6.8	4.575e+39 7.5	8.725e+39 14.3

No.

Char.

ω TO

ω LOx

ω LOy

ω LOz

I ∥

I ⊥