- TAUSONITE - SrTiO₃

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. Tetter norm-conserving pseudopotential for Ti.

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:	62		Pbnm
Lattice parameters (Å):	5.4043	5.4224		7.6510
Angles (°):	90	90		90

Symmetry (theoretical):

Space group:	62		Pbnm
Lattice parameters (Å):	5.4307	5.4063		7.6494
Angles (°):	90	90		90

Cell contents:

Number of atoms:	20
Number of atom types:	3
Chemical composition:	0

Atomic positions (theoretical):

Sr:	0.9980	0.0133	0.2500
Ti:	0.5000	0.0000	0.0000
O:	0.0416	0.4971	0.2500
O:	0.7317	0.2685	0.0215
Sr:	0.4980	0.4867	0.7500
Ti:	0.0000	0.5000	0.0000
O:	0.5416	0.0029	0.7500
O:	0.2317	0.2315	0.9785
Sr:	0.0020	0.9867	0.7500
Ti:	0.5000	0.0000	0.5000
O:	0.9584	0.5029	0.7500
O:	0.2683	0.7315	0.5215
Sr:	0.5020	0.5133	0.2500
Ti:	0.0000	0.5000	0.5000
O:	0.4584	0.9971	0.2500
O:	0.7683	0.7685	0.4785
O:	0.2683	0.7315	0.9785
O:	0.7683	0.7685	0.0215
O:	0.7317	0.2685	0.4785
O:	0.2317	0.2315	0.5215

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	B1g	71	71	71	71	1.298e+40 26.9	1.785e+40 37.0	3.084e+40 63.9
5	A1g	73	73	73	73	4.689e+39 9.7	3.026e+38 0.6	4.992e+39 10.4
6	Au	100	100	100	100
7	B3g	103	103	103	103	1.705e+38 0.4	2.345e+38 0.5	4.050e+38 0.8
8	B3u	116	119	116	116
9	A1g	119	119	119	119	9.404e+39 19.5	1.007e+38 0.2	9.505e+39 19.7
10	B2u	126	126	129	126
11	B1g	129	129	133	129	2.285e+39 4.7	3.141e+39 6.5	5.426e+39 11.3
12	B1u	145	145	145	145
13	Au	145	145	145	149
14	Au	152	152	152	152
15	B2g	155	155	155	155	2.902e+38 0.6	3.990e+38 0.8	6.892e+38 1.4
16	B1g	161	161	161	161	3.898e+39 8.1	5.360e+39 11.1	9.259e+39 19.2
17	B1u	170	170	170	173
18	B2u	173	173	175	175
19	A1g	175	175	181	180	1.144e+40 23.7	7.048e+39 14.6	1.849e+40 38.3
20	B1u	183	183	183	184
21	B3g	184	184	184	185	2.288e+37 0.0	3.145e+37 0.1	5.433e+37 0.1
22	B3u	185	192	185	192
23	B2u	192	194	201	201
24	B3u	201	212	212	212
25	A1g	212	221	221	221	3.081e+40 63.9	1.549e+38 0.3	3.096e+40 64.2
26	Au	221	228	228	227
27	B1u	228	257	257	257
28	B2u	257	271	272	272
29	B3u	272	281	281	281
30	Au	281	292	298	298
31	B3u	298	301	299	301
32	B2u	301	327	327	327
33	A1g	327	330	330	330	3.105e+39 6.4	7.082e+38 1.5	3.813e+39 7.9
34	B3u	330	334	333	334
35	B2u	334	344	344	344
36	B2g	344	354	354	354	1.920e+38 0.4	2.639e+38 0.5	4.559e+38 0.9
37	B3g	354	372	372	372	3.176e+38 0.7	4.368e+38 0.9	7.544e+38 1.6
38	B1g	372	442	448	439	3.209e+37 0.1	4.413e+37 0.1	7.622e+37 0.2
39	Au	448	448	452	448
40	B1u	452	452	453	453
41	B3u	453	454	454	454
42	B1g	454	466	463	466	3.902e+39 8.1	5.365e+39 11.1	9.267e+39 19.2
43	B2g	466	474	466	474	1.085e+39 2.2	1.491e+39 3.1	2.576e+39 5.3
44	A1g	474	485	474	481	2.756e+40 57.1	2.067e+40 42.9	4.822e+40 100.0
45	B1g	485	489	485	485	1.210e+40 25.1	1.663e+40 34.5	2.873e+40 59.6
46	B3u	500	501	500	500
47	B2u	508	508	508	508
48	Au	518	518	518	518
49	B3g	536	536	536	536	7.720e+39 16.0	1.062e+40 22.0	1.834e+40 38.0
50	B2g	539	539	539	539	1.914e+40 39.7	2.632e+40 54.6	4.546e+40 94.3
51	B1u	542	542	542	542
52	B2u	554	554	555	554
53	Au	556	556	556	556
54	A1g	561	561	561	561	6.589e+39 13.7	4.838e+39 10.0	1.143e+40 23.7
55	B2u	569	569	576	569
56	B1u	576	576	583	583
57	B3u	583	793	793	793
58	B3g	793	824	820	820	7.465e+36 0.0	1.026e+37 0.0	1.773e+37 0.0
59	B1g	832	832	832	832	2.189e+36 0.0	3.010e+36 0.0	5.199e+36 0.0
60	B2g	866	866	866	866	5.477e+37 0.1	7.531e+37 0.2	1.301e+38 0.3

No.

Char.

ω TO

ω LOx

ω LOy

ω LOz

I ∥

I ⊥