- WENDWILSONITE - Ca₂Mg(AsO₄)₂2H₂O

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:	14		P2_1/c
Lattice parameters (Å):	5.8060	12.9230		5.6280
Angles (°):	90	107.49		90

Symmetry (theoretical):

Space group:	14		P2_1/c
Lattice parameters (Å):	5.8123	12.9265		5.6318
Angles (°):	90	107.85		90

Cell contents:

Number of atoms:	38
Number of atom types:	5
Chemical composition:	0

Atomic positions (theoretical):

Ca:	0.5680	0.1202	0.2361
Mg:	0.0000	0.0000	0.0000
As:	0.2199	0.1209	0.5703
O:	0.9498	0.1795	0.4978
O:	0.2769	0.0530	0.8435
O:	0.2361	0.0366	0.3422
O:	0.4559	0.2024	0.5864
O:	0.8174	0.1363	0.9648
H:	0.9034	0.2069	0.0002
H:	0.6927	0.1503	0.7988
Ca:	0.4320	0.6202	0.2639
Mg:	0.0000	0.5000	0.5000
As:	0.7801	0.6209	0.9297
O:	0.0502	0.6795	0.0022
O:	0.7231	0.5530	0.6565
O:	0.7639	0.5366	0.1578
O:	0.5441	0.7024	0.9136
O:	0.1826	0.6363	0.5352
H:	0.0966	0.7069	0.4998
H:	0.3073	0.6503	0.7012
Ca:	0.4320	0.8798	0.7639
As:	0.7801	0.8791	0.4297
O:	0.0502	0.8205	0.5022
O:	0.7231	0.9470	0.1565
O:	0.7639	0.9634	0.6578
O:	0.5441	0.7976	0.4136
O:	0.1826	0.8637	0.0352
H:	0.0966	0.7931	0.9998
H:	0.3073	0.8497	0.2012
Ca:	0.5680	0.3798	0.7361
As:	0.2199	0.3791	0.0703
O:	0.9498	0.3205	0.9978
O:	0.2769	0.4470	0.3435
O:	0.2361	0.4634	0.8422
O:	0.4559	0.2976	0.0864
O:	0.8174	0.3637	0.4648
H:	0.9034	0.2931	0.5002
H:	0.6927	0.3497	0.2988

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	Au	61	61	61	61
5	Au	66	66	67	66
6	Ag	69	69	69	69	2.710e+39 1.8	8.347e+38 0.6	3.545e+39 2.4
7	Bg	84	84	84	84	3.008e+38 0.2	4.757e+38 0.3	7.764e+38 0.5
8	Ag	93	93	93	93	3.934e+38 0.3	1.065e+38 0.1	4.999e+38 0.3
9	Bg	110	110	110	110	6.729e+38 0.5	9.732e+38 0.7	1.646e+39 1.1
10	Bu	117	119	117	119
11	Ag	122	122	122	122	2.316e+38 0.2	1.980e+38 0.1	4.296e+38 0.3
12	Au	126	126	132	126
13	Bg	139	139	139	139	2.571e+38 0.2	4.195e+38 0.3	6.767e+38 0.5
14	Bu	143	143	143	143
15	Ag	155	155	155	155	2.702e+39 1.8	1.030e+39 0.7	3.732e+39 2.5
16	Bu	170	171	170	171
17	Au	178	178	178	178
18	Bg	179	179	179	179	3.041e+37 0.0	3.778e+37 0.0	6.819e+37 0.0
19	Bu	185	186	185	188
20	Ag	193	193	193	193	4.131e+39 2.8	2.502e+39 1.7	6.632e+39 4.5
21	Au	194	194	196	194
22	Bg	196	196	199	196	1.138e+38 0.1	1.479e+38 0.1	2.617e+38 0.2
23	Ag	199	199	202	199	8.053e+39 5.5	1.484e+39 1.0	9.537e+39 6.5
24	Bu	205	206	205	206
25	Au	206	206	206	206
26	Bg	211	211	211	211	9.971e+38 0.7	1.060e+39 0.7	2.057e+39 1.4
27	Ag	216	216	216	216	1.291e+39 0.9	1.732e+39 1.2	3.023e+39 2.1
28	Bg	221	221	221	221	1.779e+39 1.2	2.135e+39 1.5	3.914e+39 2.7
29	Bu	222	226	222	222
30	Bg	226	227	226	226	7.496e+37 0.1	1.265e+38 0.1	2.015e+38 0.1
31	Au	227	227	229	227
32	Bu	229	235	232	230
33	Au	235	237	237	235
34	Ag	239	239	239	239	2.702e+38 0.2	2.189e+38 0.1	4.891e+38 0.3
35	Bu	245	249	245	248
36	Au	250	250	252	250
37	Bg	252	252	252	252	1.020e+39 0.7	1.523e+39 1.0	2.543e+39 1.7
38	Ag	252	252	258	252	1.307e+39 0.9	1.064e+39 0.7	2.372e+39 1.6
39	Bu	258	260	260	263
40	Au	263	263	272	280
41	Bg	284	284	284	284	3.176e+38 0.2	3.974e+38 0.3	7.149e+38 0.5
42	Au	289	289	292	289
43	Ag	292	292	295	292	9.635e+38 0.7	8.949e+38 0.6	1.858e+39 1.3
44	Bu	302	310	302	310
45	Ag	310	311	310	310	4.111e+39 2.8	3.365e+39 2.3	7.476e+39 5.1
46	Bg	311	311	311	311	9.294e+38 0.6	1.051e+39 0.7	1.980e+39 1.4
47	Bu	322	322	322	326
48	Au	329	329	329	329
49	Bg	332	332	332	332	4.685e+38 0.3	6.638e+38 0.5	1.132e+39 0.8
50	Ag	336	336	336	336	2.211e+40 15.1	1.616e+40 11.0	3.827e+40 26.1
51	Bu	341	342	341	342
52	Au	342	346	347	351
53	Ag	356	356	356	356	5.494e+39 3.7	6.090e+39 4.2	1.158e+40 7.9
54	Bg	356	356	356	356	4.322e+39 2.9	4.288e+39 2.9	8.610e+39 5.9
55	Bu	358	364	358	364
56	Ag	364	364	364	364	2.391e+39 1.6	2.502e+39 1.7	4.894e+39 3.3
57	Au	364	372	366	371	1.124e+39 0.8	1.176e+39 0.8	2.300e+39 1.6
58	Bu	372	375	372	377
59	Au	377	377	378	388
60	Au	390	390	393	390
61	Bg	393	393	395	393	3.334e+39 2.3	5.627e+39 3.8	8.961e+39 6.1
62	Bu	395	400	398	400
63	Au	400	402	421	421
64	Bg	421	421	428	426	4.822e+39 3.3	7.881e+39 5.4	1.270e+40 8.7
65	Ag	428	428	433	428	5.166e+39 3.5	3.775e+39 2.6	8.941e+39 6.1
66	Bu	433	438	437	433
67	Ag	439	439	439	439	8.508e+39 5.8	5.415e+39 3.7	1.392e+40 9.5
68	Au	442	442	444	442
69	Bu	444	459	459	444
70	Bg	459	474	460	459	1.542e+39 1.1	1.723e+39 1.2	3.265e+39 2.2
71	Ag	474	486	474	474	1.213e+39 0.8	2.755e+38 0.2	1.488e+39 1.0
72	Bg	490	490	490	490	4.824e+39 3.3	5.570e+39 3.8	1.039e+40 7.1
73	Bu	517	518	517	517
74	Au	532	532	533	532
75	Ag	740	740	740	740	1.633e+40 11.1	4.163e+39 2.8	2.050e+40 14.0
76	Bu	753	759	753	753
77	Au	759	759	759	759	1.554e+38 0.1	2.618e+38 0.2	4.172e+38 0.3
78	Bg	759	761	759	759	1.110e+40 7.6	1.870e+40 12.8	2.981e+40 20.3
79	Bu	762	766	762	766
80	Au	766	769	769	769
81	Ag	769	778	778	778	7.616e+39 5.2	3.693e+39 2.5	1.131e+40 7.7
82	Bg	778	780	781	790	4.921e+39 3.4	5.251e+39 3.6	1.017e+40 6.9
83	Bg	798	798	798	798	4.480e+38 0.3	5.369e+38 0.4	9.849e+38 0.7
84	Au	799	799	799	799	9.524e+40 65.0	1.183e+39 0.8	9.643e+40 65.8
85	Ag	799	799	806	799	1.448e+41 98.8	1.799e+39 1.2	1.466e+41 100.0
86	Bu	806	811	811	811
87	Au	811	813	813	813
88	Ag	813	819	819	818	5.643e+39 3.8	3.133e+39 2.1	8.775e+39 6.0
89	Bg	819	819	820	819	6.764e+39 4.6	7.189e+39 4.9	1.395e+40 9.5
90	Bu	820	840	824	840
91	Bg	840	840	840	842	3.807e+39 2.6	4.730e+39 3.2	8.537e+39 5.8
92	Au	842	842	843	843
93	Ag	843	843	845	845	7.065e+40 48.2	1.128e+40 7.7	8.193e+40 55.9
94	Bu	851	860	851	856
95	Au	860	874	880	860
96	Bg	880	880	885	880	2.364e+39 1.6	3.129e+39 2.1	5.493e+39 3.7
97	Ag	888	888	888	888	1.659e+40 11.3	4.203e+39 2.9	2.079e+40 14.2
98	Bu	899	903	899	904
99	Ag	1023	1023	1023	1023	3.004e+38 0.2	1.046e+38 0.1	4.050e+38 0.3
100	Bu	1023	1044	1023	1027
101	Au	1059	1059	1061	1059
102	Bg	1061	1061	1063	1061	6.238e+38 0.4	1.052e+39 0.7	1.676e+39 1.1
103	Ag	1628	1628	1628	1628	1.731e+39 1.2	7.331e+38 0.5	2.464e+39 1.7
104	Bu	1630	1630	1630	1632
105	Au	1637	1637	1654	1637
106	Bg	1654	1654	1655	1654	2.428e+39 1.7	2.608e+39 1.8	5.036e+39 3.4
107	Ag	2583	2583	2583	2583	7.932e+40 54.1	2.659e+40 18.1	1.059e+41 72.2
108	Bu	2586	2618	2586	2593
109	Au	2619	2619	2701	2619
110	Bg	2701	2701	2704	2701	2.888e+40 19.7	3.392e+40 23.1	6.281e+40 42.8
111	Ag	2986	2986	2986	2986	1.042e+41 71.1	2.873e+40 19.6	1.329e+41 90.7
112	Bu	2989	2990	2989	2990
113	Au	2990	2993	2993	2993
114	Bg	2993	3006	2996	3019	9.390e+38 0.6	1.130e+39 0.8	2.069e+39 1.4

No.

Char.

ω TO

ω LOx

ω LOy

ω LOz

I ∥

I ⊥