- EDENITE - NaCa₂Mg₅Si₇AlO₂₂(OH)₂

Parameters of the Calculation

All the calculations have been done using the ABINIT software. This is a list of the most representative parameteres used during the Raman calculation.

Number of electronic bands:	96
k-points
grid:	4 4 4
number of shifts:	1
shifts:	0.5 0.5 0.5
Kinetic energy cut-off:	40 Ha [=1088.464 eV ]
eXchange-Correlation functional:	LDA pw90

Pseudopotentials:
Mg:	magnesium, fhi98PP : Trouiller-Martins-type, LDA Ceperley/Alder Perdew/Wang (1992), l= 2 local
Al:	aluminium, fhi98PP : Trouiller-Martins-type, LDA Ceperley/Alder Perdew/Wang (1992), l= 2 local
Na:	sodium, fhi98PP : Trouiller-Martins-type, LDA Ceperley/Alder Perdew/Wang (1992), l= 2 local
Si:	silicon, fhi98PP : Trouiller-Martins-type, LDA Ceperley/Alder Perdew/Wang (1992), l= 2 local
O:	oxygen, fhi98PP : Trouiller-Martins-type, LDA Ceperley/Alder Perdew/Wang (1992), l= 2 local
H:	hydrogen, fhi98PP : Trouiller-Martins-type, LDA Ceperley/Alder Perdew/Wang (1992), l= 2 local
Ca:	calcium, fhi98PP : Trouiller-Martins-type, LDA Ceperley/Alder Perdew/Wang (1992), l= 0 local

Dielectric Properties

We define:

The Born effective charges, also called dynamical charges, are tensors that correspond to the energy derivative with respect to atomic displacements and electric fields or, equivalently, to the change in atomic force due to an electric field: The sum of the Born effective charges of all nuclei in one cell must vanish, element by element, along each of the three directions of the space.
The dielectric tensors are the energy derivative with respect to two electric fields. They also relate the induced polarization to the external electric field.

Born effective charges (Z):

Mg:	2.0037	0.0083	0.0018
	0.0152	2.0002	0.0226
	-0.0015	0.0049	1.9727
Eig. Value:	2.0159	1.9942	1.9664
Mg:	2.1699	0.0429	0.0186
	0.0138	2.0413	-0.0050
	0.0485	0.0091	1.9281
Eig. Value:	2.1802	2.0355	1.9235
Mg:	1.9148	-0.0398	0.0922
	-0.0108	2.0266	-0.0137
	0.0322	-0.0062	1.9834
Eig. Value:	1.8761	2.0460	2.0027
Ca:	2.5762	0.0087	-0.0107
	0.0025	2.1134	-0.0158
	0.0059	-0.0153	2.2549
Eig. Value:	2.5763	2.1116	2.2565
Al:	2.2759	0.1472	-0.0888
	0.0394	2.8088	0.1493
	-0.1103	0.0051	2.5685
Eig. Value:	2.2236	2.8388	2.5907
Si:	2.8912	0.2323	-0.1112
	-0.0080	2.8244	0.0199
	-0.1199	0.0841	3.1445
Eig. Value:	2.9592	2.7115	3.1895
O:	-1.8212	-0.0071	-0.0607
	-0.0197	-1.6820	-0.0101
	-0.0411	0.0177	-1.6424
Eig. Value:	-1.8356	-1.6820	-1.6280
O:	-2.1626	-0.0768	-0.1685
	-0.0000	-1.4911	-0.0384
	-0.1495	-0.0541	-1.5709
Eig. Value:	-2.2059	-1.4679	-1.5508
O:	-1.1591	0.0059	0.1062
	-0.0077	-1.5118	0.0138
	0.0833	0.0054	-1.4778
Eig. Value:	-1.1331	-1.5181	-1.4975
O:	-1.6844	-0.3445	0.1061
	-0.3011	-1.9449	-0.0113
	0.1169	-0.0616	-1.5308
Eig. Value:	-1.3810	-2.1644	-1.6148
O:	-1.4620	-0.2429	0.0673
	-0.1761	-1.5717	0.3623
	0.0281	0.4160	-2.2736
Eig. Value:	-1.5940	-1.2496	-2.4637
O:	-1.5413	0.0546	0.2186
	0.1297	-1.6990	-0.4630
	0.2237	-0.4826	-2.0203
Eig. Value:	-1.4989	-1.3406	-2.4211
O:	-1.3678	-0.1037	0.0249
	-0.1188	-2.5321	0.0216
	0.0487	0.0050	-1.2477
Eig. Value:	-1.3676	-2.5428	-1.2371
H:	0.1841	0.0126	-0.0817
	0.0147	0.5269	-0.0208
	-0.0769	-0.0083	0.5203
Eig. Value:	0.1660	0.5146	0.5507
Si:	2.8015	-0.1615	-0.1352
	-0.0112	3.5331	-0.1552
	-0.1805	0.0267	3.2837
Eig. Value:	2.7414	3.5521	3.3248
Si:	2.9503	-0.3178	-0.2178
	0.0198	2.9231	0.0268
	-0.1966	-0.1420	3.3976
Eig. Value:	2.7341	3.0581	3.4788
O:	-1.9023	0.0168	-0.1056
	0.0280	-1.5706	0.0256
	-0.0883	-0.0067	-1.5453
Eig. Value:	-1.9285	-1.5692	-1.5204
O:	-2.0584	0.0885	-0.1167
	-0.0332	-1.4825	0.0202
	-0.1140	0.0592	-1.5624
Eig. Value:	-2.0860	-1.4654	-1.5518
O:	-1.1221	0.0054	0.1214
	0.0104	-1.5077	0.0015
	0.1019	-0.0013	-1.4570
Eig. Value:	-1.0882	-1.5081	-1.4905
O:	-1.7442	0.3742	0.0856
	0.3587	-1.8407	0.0669
	0.0774	0.1355	-1.5151
Eig. Value:	-1.3328	-2.1629	-1.6044
O:	-1.4487	0.3120	0.2473
	0.2592	-1.6064	-0.5788
	0.2334	-0.6275	-2.3237
Eig. Value:	-1.1756	-1.4422	-2.7610
O:	-1.4279	-0.0425	0.1743
	-0.1096	-1.6487	0.6307
	0.1887	0.6610	-2.2960
Eig. Value:	-1.4047	-1.2440	-2.7239
O:	-1.2768	0.0417	0.0337
	0.0205	-2.8520	-0.0134
	0.0527	-0.0082	-1.1618
Eig. Value:	-1.2905	-2.8526	-1.1474
H:	0.1300	-0.0044	-0.1022
	-0.0165	0.5225	-0.0165
	-0.1002	-0.0115	0.4850
Eig. Value:	0.1027	0.5296	0.5052
Mg:	2.0402	-0.0129	-0.0387
	-0.0054	1.9870	0.0061
	-0.0281	0.0030	1.9706
Eig. Value:	2.0551	1.9855	1.9571
Mg:	2.1736	-0.0126	0.0373
	-0.0015	2.0363	-0.0079
	0.0506	-0.0043	1.9320
Eig. Value:	2.1818	2.0361	1.9241
Ca:	2.5082	0.0217	-0.0451
	-0.0074	2.0968	0.0091
	-0.0349	0.0135	2.2828
Eig. Value:	2.5151	2.0959	2.2768
Si:	2.7812	0.1253	-0.1244
	0.0075	3.5843	0.1658
	-0.1554	-0.0326	3.2621
Eig. Value:	2.7356	3.5994	3.2926
Si:	2.9222	0.3569	-0.2446
	-0.0025	2.9104	-0.0043
	-0.2268	0.1690	3.4487
Eig. Value:	3.0698	2.6724	3.5391
O:	-1.9172	-0.0032	-0.1008
	-0.0266	-1.5813	-0.0238
	-0.0848	0.0103	-1.5511
Eig. Value:	-1.9401	-1.5808	-1.5287
O:	-2.0579	-0.0877	-0.1086
	0.0322	-1.4971	-0.0270
	-0.1020	-0.0668	-1.5720
Eig. Value:	-2.0821	-1.4736	-1.5713
O:	-1.7432	-0.4040	0.1066
	-0.3581	-1.8544	-0.0655
	0.0986	-0.1427	-1.5366
Eig. Value:	-1.3170	-2.1841	-1.6331
O:	-1.3971	-0.3578	0.2298
	-0.2854	-1.6015	0.5534
	0.2149	0.5983	-2.3253
Eig. Value:	-1.1251	-1.4624	-2.7365
O:	-1.4005	0.0064	0.2337
	0.0865	-1.6662	-0.6490
	0.2324	-0.6791	-2.2741
Eig. Value:	-1.4076	-1.1960	-2.7372
Si:	2.7945	-0.1096	-0.1290
	-0.0527	3.4153	-0.1937
	-0.1591	0.0116	3.1999
Eig. Value:	2.7322	3.4499	3.2276
Si:	2.9121	-0.3266	-0.2271
	-0.0343	2.8824	0.0095
	-0.2352	-0.1611	3.4442
Eig. Value:	3.0516	2.6564	3.5307
O:	-1.9926	0.0091	-0.1034
	0.0467	-1.5743	0.0296
	-0.0929	-0.0136	-1.5326
Eig. Value:	-2.0146	-1.5724	-1.5124
O:	-2.0968	0.0956	-0.1227
	-0.0155	-1.4827	0.0269
	-0.1077	0.0589	-1.5658
Eig. Value:	-2.1243	-1.4644	-1.5566
O:	-1.7178	0.3479	0.0965
	0.3242	-1.8935	0.0458
	0.0981	0.1203	-1.5363
Eig. Value:	-1.3637	-2.1530	-1.6308
O:	-1.3809	0.3652	0.1973
	0.2945	-1.6113	-0.5600
	0.1853	-0.6163	-2.3430
Eig. Value:	-1.1026	-1.4829	-2.7496
O:	-1.4209	-0.0304	0.2459
	-0.1033	-1.6573	0.6731
	0.2584	0.7244	-2.2871
Eig. Value:	-1.4070	-1.1743	-2.7839
Na:	1.2743	0.0066	-0.0011
	0.0018	1.1278	-0.0076
	0.0261	0.0030	1.0697
Eig. Value:	1.2752	1.1278	1.0688

Atom type

Dielectric tensors:

	X	Y	Z
Ɛ_∞:	2.7316	0.0000	0.0000
	0.0000	2.7546	0.0000
	0.0000	0.0000	2.7675
Eig. Value:	2.7315	2.7546	2.7675
Refractive index (N):	1.6527	0.0000	0.0000
	0.0000	1.6597	0.0000
	0.0000	0.0000	1.6636
Eig. Value:	1.6527	1.6597	1.6636
Ɛ₀:	0.0000	0.0000	0.0000
	0.0000	0.0000	0.0000
	0.0000	0.0000	0.0000
Eig. Value:	0.0000	0.0000	0.0000

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	0	0	0	0
2	0	0	0	0
3	0	0	0	0
4	91	91	91	91	1.499e+38 0.2	1.278e+38 0.2	2.777e+38 0.3
5	101	101	102	103	4.652e+38 0.6	4.266e+38 0.5	8.918e+38 1.1
6	115	116	115	115	1.553e+39 1.9	2.932e+38 0.3	1.847e+39 2.2
7	120	120	121	120	5.247e+38 0.6	2.119e+38 0.3	7.365e+38 0.9
8	129	129	129	129	1.068e+38 0.1	7.991e+37 0.1	1.867e+38 0.2
9	146	146	146	146	1.072e+38 0.1	7.230e+37 0.1	1.795e+38 0.2
10	149	150	149	150	1.201e+38 0.1	4.474e+37 0.1	1.648e+38 0.2
11	150	154	150	152	5.728e+38 0.7	1.798e+38 0.2	7.526e+38 0.9
12	161	161	161	161	2.471e+38 0.3	3.398e+38 0.4	5.869e+38 0.7
13	163	164	163	165	7.614e+38 0.9	2.985e+38 0.4	1.060e+39 1.3
14	165	165	165	166	1.152e+39 1.4	3.299e+38 0.4	1.482e+39 1.8
15	174	175	175	177	4.546e+38 0.5	2.966e+38 0.4	7.512e+38 0.9
16	182	182	182	182	8.721e+38 1.0	3.834e+37 0.0	9.104e+38 1.1
17	183	183	184	183	1.048e+39 1.2	5.687e+38 0.7	1.616e+39 1.9
18	185	188	186	186	1.694e+38 0.2	2.275e+37 0.0	1.922e+38 0.2
19	189	190	190	189	2.600e+38 0.3	1.500e+38 0.2	4.100e+38 0.5
20	198	198	199	199	4.498e+38 0.5	4.302e+38 0.5	8.800e+38 1.0
21	217	217	217	217	9.654e+37 0.1	9.422e+37 0.1	1.908e+38 0.2
22	217	217	217	219	3.544e+39 4.2	1.688e+38 0.2	3.713e+39 4.4
23	226	227	227	227	8.427e+38 1.0	2.124e+38 0.3	1.055e+39 1.3
24	231	232	232	231	3.498e+38 0.4	6.522e+37 0.1	4.150e+38 0.5
25	235	238	235	235	3.281e+39 3.9	8.314e+37 0.1	3.365e+39 4.0
26	242	242	242	242	1.712e+39 2.0	2.808e+38 0.3	1.993e+39 2.4
27	243	244	244	245	1.210e+39 1.4	1.040e+38 0.1	1.314e+39 1.6
28	246	246	246	247	6.539e+38 0.8	2.229e+38 0.3	8.768e+38 1.0
29	249	249	251	250	1.068e+39 1.3	9.696e+37 0.1	1.165e+39 1.4
30	251	251	251	251	8.151e+38 1.0	4.222e+37 0.1	8.573e+38 1.0
31	257	257	258	258	8.392e+38 1.0	3.220e+38 0.4	1.161e+39 1.4
32	263	263	263	263	5.648e+38 0.7	9.578e+37 0.1	6.606e+38 0.8
33	266	266	266	266	1.175e+38 0.1	1.186e+38 0.1	2.361e+38 0.3
34	280	282	281	280	5.329e+37 0.1	4.352e+37 0.1	9.681e+37 0.1
35	288	288	289	288	3.488e+38 0.4	5.231e+37 0.1	4.011e+38 0.5
36	290	291	291	290	1.293e+38 0.2	6.856e+37 0.1	1.979e+38 0.2
37	296	296	296	296	1.056e+38 0.1	7.180e+37 0.1	1.774e+38 0.2
38	300	301	301	302	6.170e+37 0.1	9.042e+37 0.1	1.521e+38 0.2
39	305	305	305	305	1.425e+39 1.7	8.630e+37 0.1	1.511e+39 1.8
40	308	308	308	309	6.266e+38 0.7	1.647e+37 0.0	6.430e+38 0.8
41	309	309	310	309	8.911e+37 0.1	9.697e+37 0.1	1.861e+38 0.2
42	313	313	314	313	2.787e+38 0.3	1.029e+38 0.1	3.817e+38 0.5
43	316	316	317	316	1.269e+39 1.5	1.002e+38 0.1	1.369e+39 1.6
44	334	334	334	334	2.562e+38 0.3	1.971e+38 0.2	4.532e+38 0.5
45	337	337	337	337	3.101e+38 0.4	9.663e+37 0.1	4.067e+38 0.5
46	339	339	339	339	2.777e+38 0.3	3.380e+38 0.4	6.157e+38 0.7
47	340	340	340	340	3.307e+38 0.4	2.853e+38 0.3	6.160e+38 0.7
48	344	344	344	344	2.656e+38 0.3	1.088e+38 0.1	3.744e+38 0.4
49	350	351	350	350	7.006e+38 0.8	8.556e+37 0.1	7.861e+38 0.9
50	353	353	353	353	8.498e+38 1.0	7.685e+38 0.9	1.618e+39 1.9
51	357	357	357	357	6.231e+37 0.1	4.271e+37 0.1	1.050e+38 0.1
52	362	362	362	362	2.044e+38 0.2	2.485e+38 0.3	4.529e+38 0.5
53	364	364	364	364	4.918e+38 0.6	2.735e+38 0.3	7.653e+38 0.9
54	366	366	367	366	5.922e+38 0.7	2.460e+38 0.3	8.382e+38 1.0
55	368	370	369	368	1.580e+39 1.9	4.121e+38 0.5	1.992e+39 2.4
56	370	372	370	371	2.319e+38 0.3	1.260e+38 0.2	3.580e+38 0.4
57	378	380	378	383	3.922e+38 0.5	3.858e+38 0.5	7.780e+38 0.9
58	384	385	384	384	4.817e+37 0.1	1.815e+37 0.0	6.632e+37 0.1
59	393	396	394	394	3.234e+39 3.9	1.113e+38 0.1	3.346e+39 4.0
60	396	398	396	396	1.444e+39 1.7	7.967e+37 0.1	1.524e+39 1.8
61	398	399	398	399	1.400e+38 0.2	1.493e+38 0.2	2.893e+38 0.3
62	404	407	405	404	6.264e+38 0.7	3.798e+37 0.0	6.643e+38 0.8
63	408	411	408	409	7.278e+38 0.9	1.507e+38 0.2	8.785e+38 1.0
64	411	418	411	412	6.660e+38 0.8	1.300e+38 0.2	7.960e+38 0.9
65	424	424	424	424	1.224e+39 1.5	2.162e+38 0.3	1.441e+39 1.7
66	425	425	425	426	1.725e+38 0.2	8.460e+37 0.1	2.571e+38 0.3
67	430	430	430	431	1.019e+39 1.2	1.424e+38 0.2	1.161e+39 1.4
68	431	433	432	433	6.474e+38 0.8	1.564e+38 0.2	8.038e+38 1.0
69	438	438	438	438	1.252e+38 0.1	1.094e+38 0.1	2.345e+38 0.3
70	438	439	439	439	2.511e+37 0.0	1.292e+37 0.0	3.803e+37 0.0
71	446	447	451	451	2.135e+37 0.0	1.707e+37 0.0	3.842e+37 0.0
72	452	458	452	455	5.866e+37 0.1	5.748e+37 0.1	1.161e+38 0.1
73	458	461	461	461	2.777e+38 0.3	3.503e+38 0.4	6.280e+38 0.7
74	461	472	473	472	2.712e+38 0.3	1.904e+38 0.2	4.616e+38 0.5
75	473	473	473	473	3.629e+38 0.4	2.796e+38 0.3	6.425e+38 0.8
76	473	479	479	479	7.426e+37 0.1	5.992e+37 0.1	1.342e+38 0.2
77	479	483	487	487	2.889e+38 0.3	1.222e+38 0.1	4.111e+38 0.5
78	488	494	494	493	8.126e+37 0.1	1.674e+37 0.0	9.800e+37 0.1
79	495	496	498	498	8.515e+37 0.1	7.836e+37 0.1	1.635e+38 0.2
80	498	500	502	501	2.543e+37 0.0	9.069e+36 0.0	3.450e+37 0.0
81	502	507	511	511	4.929e+38 0.6	2.768e+38 0.3	7.697e+38 0.9
82	512	512	513	513	7.746e+38 0.9	1.229e+39 1.5	2.003e+39 2.4
83	513	513	516	518	5.340e+38 0.6	7.793e+38 0.9	1.313e+39 1.6
84	518	518	521	522	5.301e+38 0.6	2.082e+38 0.2	7.383e+38 0.9
85	522	522	528	524	2.712e+38 0.3	2.201e+38 0.3	4.913e+38 0.6
86	529	530	535	535	1.253e+38 0.1	1.015e+38 0.1	2.268e+38 0.3
87	537	543	556	555	7.121e+38 0.8	8.188e+38 1.0	1.531e+39 1.8
88	558	561	560	561	8.019e+38 1.0	9.184e+38 1.1	1.720e+39 2.0
89	561	563	564	578	1.122e+38 0.1	1.310e+38 0.2	2.431e+38 0.3
90	580	580	580	583	2.666e+38 0.3	2.977e+38 0.4	5.643e+38 0.7
91	595	595	599	595	2.280e+38 0.3	2.084e+38 0.2	4.364e+38 0.5
92	612	612	617	613	1.746e+39 2.1	1.974e+37 0.0	1.766e+39 2.1
93	637	638	642	637	1.627e+39 1.9	2.130e+39 2.5	3.757e+39 4.5
94	650	650	650	650	1.830e+38 0.2	1.281e+38 0.2	3.110e+38 0.4
95	654	654	662	654	3.301e+40 39.3	7.442e+37 0.1	3.308e+40 39.4
96	662	663	662	662	8.044e+38 1.0	1.036e+38 0.1	9.079e+38 1.1
97	670	671	673	670	5.269e+39 6.3	5.717e+37 0.1	5.326e+39 6.3
98	680	680	680	681	4.976e+38 0.6	4.725e+38 0.6	9.701e+38 1.2
99	704	704	704	705	1.846e+38 0.2	1.621e+38 0.2	3.467e+38 0.4
100	713	713	714	714	1.152e+39 1.4	1.918e+38 0.2	1.344e+39 1.6
101	723	723	724	723	4.479e+38 0.5	2.490e+38 0.3	6.969e+38 0.8
102	735	735	735	742	5.672e+38 0.7	6.514e+37 0.1	6.324e+38 0.8
103	858	859	858	858	4.384e+38 0.5	5.112e+38 0.6	9.496e+38 1.1
104	862	863	862	870	3.744e+38 0.4	1.511e+38 0.2	5.255e+38 0.6
105	895	895	896	897	1.797e+38 0.2	6.604e+37 0.1	2.457e+38 0.3
106	903	904	903	904	3.769e+38 0.4	3.639e+38 0.4	7.408e+38 0.9
107	904	905	905	907	2.261e+39 2.7	1.598e+38 0.2	2.421e+39 2.9
108	910	910	912	914	5.748e+37 0.1	6.024e+37 0.1	1.177e+38 0.1
109	914	924	920	920	5.609e+38 0.7	1.704e+38 0.2	7.312e+38 0.9
110	930	930	931	937	1.631e+39 1.9	4.694e+37 0.1	1.678e+39 2.0
111	939	941	941	946	4.037e+39 4.8	2.692e+38 0.3	4.306e+39 5.1
112	946	947	949	952	4.307e+38 0.5	7.274e+37 0.1	5.034e+38 0.6
113	952	955	968	971	1.531e+39 1.8	2.601e+38 0.3	1.791e+39 2.1
114	973	987	987	991	3.216e+39 3.8	6.834e+38 0.8	3.899e+39 4.6
115	991	996	1002	1002	1.699e+38 0.2	6.071e+37 0.1	2.306e+38 0.3
116	1002	1007	1004	1007	3.608e+39 4.3	1.998e+38 0.2	3.807e+39 4.5
117	1008	1018	1015	1028	2.145e+39 2.6	1.576e+38 0.2	2.303e+39 2.7
118	1028	1030	1029	1030	2.950e+39 3.5	1.390e+38 0.2	3.089e+39 3.7
119	1030	1034	1031	1034	1.103e+38 0.1	7.664e+37 0.1	1.869e+38 0.2
120	1040	1040	1044	1040	1.010e+39 1.2	9.561e+37 0.1	1.106e+39 1.3
121	1044	1047	1059	1044	4.353e+39 5.2	5.583e+38 0.7	4.911e+39 5.8
122	1060	1066	1067	1060	1.091e+40 13.0	1.809e+39 2.2	1.271e+40 15.1
123	1070	1102	1070	1071	2.015e+38 0.2	1.197e+38 0.1	3.212e+38 0.4
124	1115	1124	1136	1115	7.905e+40 94.2	4.896e+39 5.8	8.395e+40 100.0
125	3708	3708	3708	3708	1.036e+40 12.3	6.429e+38 0.8	1.101e+40 13.1
126	3717	3717	3717	3717

No.

Char.

ω TO

ω LOx

ω LOy

ω LOz

I ∥

I ⊥

I Total

You can define the size of the supercell for the visualization of the vibration.

Normalized

Raw

Options for intensity.

Single Crystal Raman spectra

Single crystal Raman spectrum

The Raman measurements performed on single crystals employ polarized lasers and allow for the selection of specific elements of the individual Raman tensors of the Raman-active modes.

By convention, in the following we assume a measurement as X(XZ)Z, i.e. incident laser polarized along the X axis, emergent light polarized along the Z axis. If the crystal is aligned with the xyz reference frame, we sample the α_xz element. As you rotate the crystal you can sample other entries of the Raman tensor or various linear combineations.