-    PARADAMITE     -    Zn2AsO4OH

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):  5.6380  5.8270  6.6920 
Angles (°):  103.25  104.37  87.72 

Symmetry (theoretical): 

Space group:  2  P-1 
Lattice parameters (Å):  5.5242  5.7545  6.6976 
Angles (°):  103.39  104.27  88.18 

Cell contents: 

Number of atoms:  18 
Number of atom types:  4 
Chemical composition:  0 

Atomic positions (theoretical):

Zn:  0.3932  0.2477  0.4993 
As:  0.0229  0.7376  0.1852 
Zn:  0.8275  0.2487  0.2750 
As:  0.7496  0.9629  0.1415 
H:  0.9534  0.3870  0.1252 
Zn:  0.5672  0.3893  0.3276 
Zn:  0.9584  0.7470  0.4913 
Zn:  0.3565  0.8959  0.2988 
Zn:  0.4454  0.9100  0.1898 
Zn:  0.6068  0.7523  0.5007 
Zn:  0.9771  0.2624  0.8148 
Zn:  0.1725  0.7513  0.7250 
Zn:  0.2504  0.0371  0.8585 
Zn:  0.0466  0.6130  0.8748 
Zn:  0.4328  0.6107  0.6724 
Zn:  0.0416  0.2530  0.5087 
Zn:  0.6435  0.1041  0.7012 
Zn:  0.5546  0.0900  0.8102 
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
Ac
0
0
0
0
4
Ag
83
83
83
83
2.716e+39
0.8
2.174e+39
0.7
4.890e+39
1.5
5
Au
85
88
85
85
6
Ag
99
99
99
99
2.243e+39
0.7
2.131e+39
0.7
4.375e+39
1.3
7
Ag
114
114
114
114
4.828e+39
1.5
8.154e+38
0.2
5.644e+39
1.7
8
Ag
119
119
119
119
1.273e+39
0.4
8.889e+38
0.3
2.161e+39
0.7
9
Au
133
135
133
134
10
Ag
138
138
138
138
8.031e+38
0.2
5.395e+38
0.2
1.343e+39
0.4
11
Au
148
148
148
156
12
Au
165
165
168
168
13
Ag
168
168
170
169
8.078e+39
2.5
1.045e+40
3.2
1.853e+40
5.7
14
Au
175
176
176
176
15
Ag
176
176
183
186
1.248e+40
3.8
1.885e+39
0.6
1.436e+40
4.4
16
Ag
186
186
186
193
1.476e+40
4.5
1.866e+39
0.6
1.663e+40
5.1
17
Au
199
208
216
204
18
Au
229
234
233
234
19
Ag
234
241
234
234
1.826e+40
5.6
8.556e+39
2.6
2.682e+40
8.2
20
Ag
241
241
241
241
5.844e+40
17.8
2.014e+39
0.6
6.046e+40
18.4
21
Au
259
260
259
264
22
Ag
282
282
282
282
2.073e+40
6.3
7.055e+39
2.2
2.779e+40
8.5
23
Ag
286
286
286
286
1.283e+40
3.9
1.129e+40
3.4
2.412e+40
7.4
24
Au
288
288
288
288
25
Au
303
303
304
304
26
Ag
319
319
319
319
5.580e+39
1.7
3.345e+39
1.0
8.924e+39
2.7
27
Au
323
325
360
327
28
Ag
372
372
372
372
1.787e+40
5.5
7.213e+39
2.2
2.508e+40
7.7
29
Ag
377
377
377
377
2.098e+40
6.4
5.096e+39
1.6
2.608e+40
8.0
30
Au
388
389
397
399
31
Ag
418
418
418
418
3.219e+40
9.8
9.013e+39
2.7
4.121e+40
12.6
32
Au
433
440
433
442
33
Au
445
455
446
447
34
Ag
466
466
466
466
3.830e+40
11.7
1.078e+40
3.3
4.908e+40
15.0
35
Au
470
476
471
474
36
Au
478
480
480
480
37
Ag
480
485
492
492
4.965e+40
15.1
2.963e+40
9.0
7.928e+40
24.2
38
Ag
492
492
494
506
5.703e+39
1.7
4.516e+39
1.4
1.022e+40
3.1
39
Au
510
523
523
513
40
Ag
523
536
524
523
7.423e+39
2.3
7.065e+39
2.2
1.449e+40
4.4
41
Au
769
773
771
772
42
Ag
774
774
774
774
1.319e+41
40.3
8.077e+39
2.5
1.400e+41
42.7
43
Au
779
784
784
779
44
Au
785
794
794
793
45
Ag
794
794
794
794
1.454e+41
44.3
1.113e+40
3.4
1.565e+41
47.7
46
Au
794
822
817
822
47
Ag
822
840
822
845
3.096e+41
94.5
1.819e+40
5.5
3.278e+41
100.0
48
Ag
857
857
857
857
5.667e+40
17.3
1.124e+40
3.4
6.791e+40
20.7
49
Ag
866
866
866
866
1.715e+41
52.3
6.818e+40
20.8
2.397e+41
73.1
50
Au
898
910
918
898
51
Ag
982
982
982
982
4.694e+39
1.4
5.556e+39
1.7
1.025e+40
3.1
52
Au
1003
1016
1010
1007
53
Au
3219
3234
3222
3225
54
Ag
3234
3235
3234
3234
1.809e+41
55.2
2.958e+40
9.0
2.105e+41
64.2
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.