- TREMOLITE - []CaMg₅Si₈O₂₂(OH)₂

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:	12		C2/m
Lattice parameters (Å):	9.8359	18.0450		5.2752
Angles (°):	90	104.750		90

Symmetry (theoretical):

Space group:	12		C2/m
Lattice parameters (Å):	10.2499	10.2499		5.2512
Angles (°):	82.94	97.05		58.02

Cell contents:

Number of atoms:	41
Number of atom types:	5
Chemical composition:	0

Atomic positions (theoretical):

Si:	0.3583	0.8111	0.2953
Si:	0.4568	0.8874	0.8044
Mg:	0.0883	0.0883	0.5000
Mg:	0.1772	0.1772	0.0000
Mg:	0.0000	0.0000	0.0000
Ca:	0.2808	0.2808	0.5000
H:	0.2069	0.7931	0.7669
O:	0.1952	0.9789	0.2168
O:	0.2897	0.0542	0.7245
O:	0.1063	0.8937	0.7148
O:	0.3869	0.1178	0.2025
O:	0.4748	0.7934	0.0990
O:	0.4575	0.7815	0.5865
O:	0.3274	0.6726	0.2917
Si:	0.8111	0.3583	0.7047
Si:	0.8874	0.4568	0.1956
H:	0.7931	0.2069	0.2331
O:	0.9789	0.1952	0.7832
O:	0.0542	0.2897	0.2755
O:	0.8937	0.1063	0.2852
O:	0.1178	0.3869	0.7975
O:	0.7934	0.4748	0.9010
O:	0.7815	0.4575	0.4135
O:	0.6726	0.3274	0.7083
Si:	0.6417	0.1889	0.7047
Si:	0.5432	0.1126	0.1956
Mg:	0.9117	0.9117	0.5000
Mg:	0.8228	0.8228	0.0000
Ca:	0.7192	0.7192	0.5000
O:	0.8048	0.0211	0.7832
O:	0.7103	0.9458	0.2755
O:	0.6131	0.8822	0.7975
O:	0.5252	0.2066	0.9010
O:	0.5425	0.2185	0.4135
Si:	0.1889	0.6417	0.2953
Si:	0.1126	0.5432	0.8044
O:	0.0211	0.8048	0.2168
O:	0.9458	0.7103	0.7245
O:	0.8822	0.6131	0.2025
O:	0.2066	0.5252	0.0990
O:	0.2185	0.5425	0.5865

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	Bg	78	78	78	78	5.752e+37 0.1	7.909e+37 0.2	1.366e+38 0.3
5	Au	113	113	114	113
6	Bg	115	115	115	115	1.680e+38 0.4	2.053e+38 0.5	3.733e+38 0.9
7	Ag	119	119	119	119	1.279e+39 3.2	3.982e+38 1.0	1.678e+39 4.2
8	Bu	132	137	132	139
9	Bg	146	146	146	146	2.644e+38 0.7	3.231e+38 0.8	5.875e+38 1.5
10	Ag	151	151	151	151	1.872e+39 4.7	3.756e+38 0.9	2.248e+39 5.6
11	Bu	154	156	154	156
12	Bg	156	157	156	157	3.530e+38 0.9	5.908e+38 1.5	9.438e+38 2.4
13	Bu	167	168	167	168
14	Bu	171	172	171	173
15	Ag	174	174	174	174	4.935e+39 12.3	2.678e+38 0.7	5.203e+39 13.0
16	Au	183	183	185	183
17	Bg	191	191	191	191	1.518e+38 0.4	2.515e+38 0.6	4.033e+38 1.0
18	Bg	210	210	210	210	5.005e+38 1.3	6.362e+38 1.6	1.137e+39 2.8
19	Bu	211	211	211	212
20	Au	212	212	215	212
21	Ag	217	217	217	217	9.379e+39 23.5	2.086e+38 0.5	9.587e+39 24.0
22	Bu	220	222	220	220
23	Ag	225	225	225	225	2.051e+39 5.1	9.522e+38 2.4	3.003e+39 7.5
24	Au	232	232	236	232
25	Bu	238	239	238	240
26	Ag	243	243	243	243	2.352e+39 5.9	1.416e+38 0.4	2.494e+39 6.2
27	Bg	244	244	244	244	2.846e+37 0.1	3.914e+37 0.1	6.760e+37 0.2
28	Bu	250	251	250	250
29	Au	251	252	251	251
30	Bg	261	261	261	261	2.804e+38 0.7	2.980e+38 0.7	5.784e+38 1.4
31	Bu	277	279	277	277
32	Au	280	280	281	280
33	Ag	285	285	285	285	8.729e+38 2.2	1.264e+38 0.3	9.993e+38 2.5
34	Bg	294	294	294	294	1.843e+37 0.0	2.899e+37 0.1	4.741e+37 0.1
35	Bu	295	295	295	296
36	Au	296	296	298	296
37	Ag	299	299	299	299	1.224e+39 3.1	6.911e+37 0.2	1.293e+39 3.2
38	Bg	303	303	303	303	7.020e+37 0.2	8.719e+37 0.2	1.574e+38 0.4
39	Ag	307	307	307	307	1.461e+38 0.4	9.980e+37 0.2	2.459e+38 0.6
40	Au	312	312	316	312
41	Bg	323	323	323	323	2.439e+37 0.1	2.759e+37 0.1	5.198e+37 0.1
42	Ag	325	325	325	325	5.694e+38 1.4	2.188e+38 0.5	7.882e+38 2.0
43	Bu	331	331	331	331
44	Au	333	333	333	333
45	Bg	337	337	337	337	4.956e+38 1.2	2.422e+38 0.6	7.378e+38 1.8
46	Bg	337	337	337	337	2.085e+38 0.5	1.032e+38 0.3	3.117e+38 0.8
47	Bu	345	346	345	345
48	Bu	346	347	346	347
49	Bg	347	348	347	347	7.134e+38 1.8	1.179e+39 3.0	1.893e+39 4.7
50	Ag	348	353	348	348	4.553e+38 1.1	2.508e+37 0.1	4.803e+38 1.2
51	Bg	354	354	354	354	1.400e+37 0.0	2.148e+37 0.1	3.548e+37 0.1
52	Bg	354	354	360	354	1.183e+38 0.3	1.815e+38 0.5	2.997e+38 0.7
53	Ag	360	360	360	360	5.000e+39 12.5	5.218e+38 1.3	5.522e+39 13.8
54	Bu	363	365	363	366
55	Bg	368	368	368	368	6.787e+38 1.7	7.579e+38 1.9	1.437e+39 3.6
56	Bu	384	385	384	385
57	Au	385	385	385	386
58	Ag	386	386	386	388	3.032e+39 7.6	1.448e+38 0.4	3.177e+39 7.9
59	Bu	392	395	392	393
60	Au	395	401	397	395
61	Bg	401	405	401	401	6.573e+37 0.2	1.049e+38 0.3	1.707e+38 0.4
62	Bu	412	412	412	412
63	Ag	412	414	412	412	4.871e+39 12.2	3.121e+38 0.8	5.183e+39 13.0
64	Au	414	419	414	414
65	Bg	423	423	423	423	1.294e+38 0.3	1.586e+38 0.4	2.879e+38 0.7
66	Ag	425	425	425	425	1.474e+38 0.4	1.504e+38 0.4	2.978e+38 0.7
67	Au	425	425	426	425
68	Bu	428	428	428	433
69	Bu	445	446	445	446
70	Au	446	459	461	461
71	Bu	461	468	468	468
72	Bg	468	473	473	473	9.964e+37 0.2	1.125e+38 0.3	2.122e+38 0.5
73	Ag	473	484	478	484	1.273e+38 0.3	9.430e+37 0.2	2.216e+38 0.6
74	Au	484	485	485	485
75	Bg	485	487	491	488	2.620e+37 0.1	2.831e+37 0.1	5.451e+37 0.1
76	Au	491	491	492	491
77	Bu	492	494	498	496
78	Bu	498	500	501	501
79	Bg	501	501	503	503	2.331e+38 0.6	3.932e+38 1.0	6.263e+38 1.6
80	Ag	503	503	505	507	4.432e+38 1.1	2.171e+38 0.5	6.603e+38 1.7
81	Au	507	507	514	514
82	Ag	514	514	518	518	6.058e+38 1.5	2.623e+38 0.7	8.681e+38 2.2
83	Bg	518	518	529	523	6.355e+38 1.6	7.853e+38 2.0	1.421e+39 3.6
84	Bu	529	542	553	567
85	Ag	569	569	569	569	2.860e+38 0.7	8.121e+37 0.2	3.672e+38 0.9
86	Bu	621	621	621	625
87	Bg	631	631	631	631	3.886e+38 1.0	4.652e+38 1.2	8.538e+38 2.1
88	Ag	634	634	634	634	1.450e+39 3.6	1.326e+39 3.3	2.776e+39 6.9
89	Bu	644	647	644	644
90	Au	647	647	647	647
91	Ag	653	653	653	653	3.986e+40 99.7	1.109e+38 0.3	3.997e+40 100.0
92	Au	670	670	680	670
93	Bg	680	680	688	680	1.568e+39 3.9	1.951e+39 4.9	3.519e+39 8.8
94	Au	707	707	707	707
95	Bu	721	721	721	721
96	Bg	722	722	722	722	6.438e+38 1.6	1.084e+39 2.7	1.728e+39 4.3
97	Ag	730	730	730	730	5.597e+38 1.4	3.758e+38 0.9	9.355e+38 2.3
98	Ag	734	734	734	734	2.291e+38 0.6	5.602e+37 0.1	2.851e+38 0.7
99	Bu	737	737	737	752
100	Bg	880	880	880	880	1.152e+38 0.3	1.811e+38 0.5	2.963e+38 0.7
101	Au	889	889	896	889
102	Bu	896	904	900	896
103	Ag	906	906	906	906	7.131e+39 17.8	2.965e+38 0.7	7.428e+39 18.6
104	Au	923	923	923	923
105	Bg	924	924	924	924	7.264e+37 0.2	9.380e+37 0.2	1.664e+38 0.4
106	Bu	926	926	926	926
107	Ag	926	926	926	935	8.207e+38 2.1	4.000e+38 1.0	1.221e+39 3.1
108	Bg	935	935	935	962	2.027e+37 0.1	3.021e+37 0.1	5.048e+37 0.1
109	Au	962	962	971	969
110	Bu	971	1003	1001	1003
111	Bg	1003	1007	1003	1012	4.900e+38 1.2	6.605e+38 1.7	1.150e+39 2.9
112	Ag	1012	1012	1012	1018	4.340e+39 10.9	8.607e+38 2.2	5.201e+39 13.0
113	Bg	1018	1018	1018	1021	8.386e+37 0.2	9.515e+37 0.2	1.790e+38 0.4
114	Au	1021	1021	1021	1021
115	Bu	1021	1023	1023	1024
116	Bu	1024	1038	1024	1038
117	Ag	1038	1051	1038	1051	1.989e+40 49.7	1.143e+39 2.9	2.103e+40 52.6
118	Ag	1051	1072	1051	1051	9.772e+38 2.4	8.453e+38 2.1	1.822e+39 4.6
119	Au	1072	1078	1078	1072
120	Bg	1078	1086	1110	1078	1.114e+38 0.3	1.563e+38 0.4	2.677e+38 0.7
121	Au	1111	1111	1142	1111
122	Ag	3665	3665	3665	3665	1.730e+40 43.3	8.381e+38 2.1	1.813e+40 45.4
123	Bu	3666	3666	3666	3666

No.

Char.

ω TO

ω LOx

ω LOy

ω LOz

I ∥

I ⊥