-    XENOTIME     -    YPO4

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:  141  I4_1/amd 
Lattice parameters (Å):  6.8947  6.8947  6.0276 
Angles (°):  90.0  90.0  90.0 

Symmetry (theoretical): 

Space group:  141  I4_1/amd 
Lattice parameters (Å):  5.5148  5.5148  5.5148 
Angles (°):  105.9  105.9  116.9 

Cell contents: 

Number of atoms:  12 
Number of atom types:  3 
Chemical composition:  0 

Atomic positions (theoretical):

Y:  0.0000  0.0000  0.0000 
P:  0.5000  0.5000  0.0000 
O:  0.5109  0.3328  0.1780 
O:  0.1548  0.3328  0.8220 
Y:  0.7500  0.2500  0.5000 
P:  0.2500  0.7500  0.5000 
O:  0.0828  0.4048  0.3220 
O:  0.0828  0.7609  0.6780 
O:  0.5952  0.9172  0.6780 
O:  0.2391  0.9172  0.3220 
O:  0.6672  0.4891  0.8220 
O:  0.6672  0.8452  0.1780 
Atom type  X  Y  Z 

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: 

Size:

 Nx:  Ny:  Nz: 
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
a
0
0
0
0
4
B1u
110
110
110
110
5
Eg
170
170
170
170
6.609e+38
0.5
9.087e+38
0.7
1.570e+39
1.2
6
Eg
170
170
170
170
6.609e+38
0.5
9.087e+38
0.7
1.570e+39
1.2
7
B1g
207
207
207
207
1.233e+39
0.9
9.245e+38
0.7
2.157e+39
1.6
8
Eg
237
237
237
237
9.187e+38
0.7
1.263e+39
0.9
2.182e+39
1.6
9
Eg
237
237
237
237
9.187e+38
0.7
1.263e+39
0.9
2.182e+39
1.6
10
A2g
244
244
244
244
11
Eu
271
271
271
271
12
Eu
271
316
316
271
13
B2g
316
318
318
316
4.480e+39
3.3
6.160e+39
4.6
1.064e+40
7.9
14
A2u
360
360
360
370
15
Eg
370
370
370
370
1.017e+40
7.5
1.406e+40
10.4
2.423e+40
18.0
16
Eg
370
370
370
373
1.017e+40
7.5
1.390e+40
10.3
2.407e+40
17.8
17
B1g
373
373
373
414
5.917e+38
0.4
4.438e+38
0.3
1.035e+39
0.8
18
Eu
414
414
414
414
19
Eu
414
415
415
415
20
A1u
415
434
434
465
21
Eu
511
511
511
511
22
Eu
511
518
518
511
23
A1g
518
536
536
518
2.435e+40
18.1
1.544e+40
11.5
3.979e+40
29.5
24
Eg
586
586
586
586
2.669e+39
2.0
3.739e+39
2.8
6.408e+39
4.8
25
Eg
586
586
586
586
2.669e+39
2.0
3.602e+39
2.7
6.271e+39
4.7
26
B2u
589
589
589
589
27
A2u
664
664
664
691
28
B1g
691
691
691
702
9.870e+38
0.7
7.402e+38
0.5
1.727e+39
1.3
29
B2u
1013
1013
1013
1013
30
Eu
1013
1013
1013
1013
31
Eu
1013
1029
1029
1013
32
A1g
1029
1061
1061
1029
1.346e+41
99.8
2.139e+38
0.2
1.348e+41
100.0
33
Eg
1061
1061
1061
1061
5.914e+39
4.4
8.132e+39
6.0
1.405e+40
10.4
34
Eg
1061
1094
1094
1061
5.914e+39
4.4
8.132e+39
6.0
1.405e+40
10.4
35
A2u
1094
1097
1097
1097
36
B1g
1097
1149
1149
1214
3.939e+40
29.2
2.955e+40
21.9
6.894e+40
51.1
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.

Nx: 
Ny: 
Nz: 
Normalized
Raw
Options for intensity.