- BASSANITE - CaSO₄0.625H₂O

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 Unstable structure.

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:	5		C2
Lattice parameters (Å):	17.5180	6.9291		12.0344
Angles (°):	90	133.655		90

Symmetry (theoretical):

Space group:	5		C2
Lattice parameters (Å):	9.3673	9.3673		12.0654
Angles (°):	50.18	129.81		136.42

Cell contents:

Number of atoms:	45
Number of atom types:	4
Chemical composition:	0

Atomic positions (theoretical):

Ca:	0.6262	0.9582	0.5754
Ca:	0.1863	0.5089	0.0572
Ca:	0.5056	0.5056	0.5000
Ca:	0.0017	0.0017	1.0000
S:	0.3965	0.2218	0.3122
S:	0.2525	0.7533	0.2457
S:	0.9157	0.7585	0.8053
O:	0.4002	0.3735	0.3212
O:	0.2814	0.2335	0.1514
O:	0.2935	0.9953	0.4153
O:	0.6256	0.2917	0.3608
O:	0.2974	0.9518	0.1104
O:	0.5802	0.2205	0.7606
O:	0.4345	0.7987	0.3882
O:	0.8621	0.5317	0.9066
O:	0.1522	0.8997	0.8322
O:	0.8473	0.8291	0.8357
O:	0.7910	0.7736	0.6422
O:	0.6800	0.0479	0.7549
O:	0.1644	0.1644	0.5000
O:	0.3529	0.6734	0.8873
H:	0.4625	0.8217	0.8422
H:	0.2956	0.5862	0.8348
H:	0.1133	0.0505	0.5876
Ca:	0.9582	0.6262	0.4246
Ca:	0.5089	0.1863	0.9428
S:	0.2218	0.3965	0.6878
S:	0.7533	0.2525	0.7543
S:	0.7585	0.9157	0.1947
O:	0.3735	0.4002	0.6788
O:	0.2335	0.2814	0.8486
O:	0.9953	0.2935	0.5847
O:	0.2917	0.6256	0.6392
O:	0.9518	0.2974	0.8896
O:	0.2205	0.5802	0.2394
O:	0.7987	0.4345	0.6118
O:	0.5317	0.8621	0.0934
O:	0.8997	0.1522	0.1678
O:	0.8291	0.8473	0.1643
O:	0.7736	0.7910	0.3578
O:	0.0479	0.6800	0.2451
O:	0.6734	0.3529	0.1127
H:	0.8217	0.4625	0.1578
H:	0.5862	0.2956	0.1652
H:	0.0505	0.1133	0.4124

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	B	-148	-147	-148	-142
2	B	-48	-48	-48	-47
3	A	-39	-39	-39	-39
4	Ac	0	0	0	0
5	Ac	0	0	0	0
6	Ac	0	0	0	0
7	B	66	73	66	70	1.874e+38 0.2	1.999e+38 0.2	3.873e+38 0.3
8	A	77	77	78	77	4.755e+38 0.4	4.295e+38 0.4	9.050e+38 0.8
9	B	80	81	80	83	2.020e+37 0.0	3.289e+37 0.0	5.309e+37 0.0
10	A	89	89	89	89	7.861e+37 0.1	7.965e+37 0.1	1.583e+38 0.1
11	B	90	91	90	90	8.243e+37 0.1	1.287e+38 0.1	2.112e+38 0.2
12	A	101	101	101	101	4.642e+38 0.4	1.501e+38 0.1	6.143e+38 0.5
13	A	109	109	109	109	6.610e+38 0.6	2.886e+38 0.2	9.496e+38 0.8
14	B	110	111	110	111	1.559e+38 0.1	2.144e+38 0.2	3.703e+38 0.3
15	A	111	111	111	111	1.585e+38 0.1	6.996e+37 0.1	2.284e+38 0.2
16	B	115	116	115	116	1.527e+37 0.0	2.100e+37 0.0	3.627e+37 0.0
17	B	122	123	122	123	1.830e+38 0.2	2.171e+38 0.2	4.001e+38 0.3
18	A	124	124	124	124	4.727e+38 0.4	6.085e+36 0.0	4.788e+38 0.4
19	A	126	126	126	126	1.422e+38 0.1	4.209e+37 0.0	1.843e+38 0.2
20	A	130	130	130	130	1.335e+38 0.1	9.850e+37 0.1	2.320e+38 0.2
21	B	131	131	131	131	3.326e+37 0.0	5.593e+37 0.0	8.919e+37 0.1
22	A	134	134	135	134	3.253e+38 0.3	1.042e+38 0.1	4.295e+38 0.4
23	B	136	136	136	136	6.887e+37 0.1	1.069e+38 0.1	1.757e+38 0.1
24	A	140	140	140	140	2.981e+38 0.3	9.052e+37 0.1	3.886e+38 0.3
25	B	142	142	142	142	1.976e+37 0.0	2.192e+37 0.0	4.167e+37 0.0
26	A	142	142	142	142	4.400e+38 0.4	3.355e+38 0.3	7.755e+38 0.7
27	B	147	147	147	147	1.402e+38 0.1	2.026e+38 0.2	3.429e+38 0.3
28	B	151	151	151	151	1.057e+38 0.1	1.370e+38 0.1	2.427e+38 0.2
29	A	153	153	154	153	1.184e+38 0.1	1.040e+38 0.1	2.224e+38 0.2
30	B	154	154	154	155	1.016e+37 0.0	1.173e+37 0.0	2.189e+37 0.0
31	A	158	158	158	158	9.475e+37 0.1	7.842e+37 0.1	1.732e+38 0.1
32	B	166	169	166	166	1.119e+38 0.1	1.189e+38 0.1	2.307e+38 0.2
33	A	169	169	169	169	2.539e+38 0.2	8.124e+37 0.1	3.351e+38 0.3
34	A	174	174	174	174	3.487e+37 0.0	1.229e+37 0.0	4.716e+37 0.0
35	B	175	175	175	175	8.727e+37 0.1	1.336e+38 0.1	2.209e+38 0.2
36	A	176	176	178	176	3.414e+38 0.3	1.757e+38 0.1	5.172e+38 0.4
37	B	179	181	179	180	3.891e+37 0.0	4.689e+37 0.0	8.581e+37 0.1
38	A	181	182	187	181	1.396e+38 0.1	2.440e+37 0.0	1.640e+38 0.1
39	B	187	188	188	187	3.482e+37 0.0	4.787e+37 0.0	8.269e+37 0.1
40	B	188	188	191	195	1.604e+38 0.1	2.381e+38 0.2	3.985e+38 0.3
41	B	201	201	201	201	5.139e+36 0.0	7.066e+36 0.0	1.220e+37 0.0
42	B	204	207	204	206	5.164e+37 0.0	6.053e+37 0.1	1.122e+38 0.1
43	A	207	208	208	207	5.794e+38 0.5	1.297e+38 0.1	7.091e+38 0.6
44	A	208	208	209	208	2.943e+38 0.3	1.997e+38 0.2	4.941e+38 0.4
45	A	213	213	214	213	1.126e+38 0.1	5.360e+37 0.0	1.662e+38 0.1
46	B	214	216	218	214	7.863e+37 0.1	8.362e+37 0.1	1.623e+38 0.1
47	A	219	219	219	219	2.169e+38 0.2	1.756e+38 0.1	3.925e+38 0.3
48	B	219	221	220	220	1.134e+38 0.1	1.559e+38 0.1	2.694e+38 0.2
49	B	230	231	230	233	5.640e+36 0.0	9.309e+36 0.0	1.495e+37 0.0
50	B	235	235	235	235	2.357e+38 0.2	3.762e+38 0.3	6.119e+38 0.5
51	A	236	236	236	236	1.508e+38 0.1	9.200e+37 0.1	2.428e+38 0.2
52	A	240	240	240	240	8.745e+37 0.1	6.448e+37 0.1	1.519e+38 0.1
53	B	243	248	243	244	1.694e+38 0.1	2.329e+38 0.2	4.023e+38 0.3
54	A	250	250	252	250	5.859e+37 0.1	2.090e+37 0.0	7.949e+37 0.1
55	B	252	254	254	253	5.963e+37 0.1	6.371e+37 0.1	1.233e+38 0.1
56	A	255	255	258	255	1.882e+38 0.2	2.070e+38 0.2	3.953e+38 0.3
57	B	258	270	267	270	1.075e+37 0.0	1.478e+37 0.0	2.552e+37 0.0
58	A	270	275	275	272	2.786e+38 0.2	6.585e+37 0.1	3.444e+38 0.3
59	B	275	279	288	286	1.892e+37 0.0	3.023e+37 0.0	4.915e+37 0.0
60	B	288	310	295	320	1.692e+37 0.0	2.801e+37 0.0	4.493e+37 0.0
61	A	327	327	332	327	2.789e+38 0.2	3.935e+37 0.0	3.183e+38 0.3
62	B	338	344	338	341	2.075e+38 0.2	3.238e+38 0.3	5.313e+38 0.5
63	A	350	350	350	350	1.024e+38 0.1	2.223e+36 0.0	1.046e+38 0.1
64	B	352	358	352	356	1.185e+38 0.1	1.975e+38 0.2	3.160e+38 0.3
65	B	370	374	370	370	6.842e+38 0.6	1.077e+39 0.9	1.761e+39 1.5
66	A	382	382	383	382	1.285e+39 1.1	1.432e+39 1.2	2.717e+39 2.3
67	A	395	395	396	395	5.720e+39 4.9	5.360e+39 4.6	1.108e+40 9.5
68	B	402	402	402	403	3.307e+39 2.8	5.531e+39 4.7	8.837e+39 7.5
69	A	412	412	412	412	5.415e+38 0.5	4.411e+38 0.4	9.826e+38 0.8
70	B	420	421	420	420	2.756e+38 0.2	4.394e+38 0.4	7.150e+38 0.6
71	B	422	423	422	422	9.670e+38 0.8	1.617e+39 1.4	2.584e+39 2.2
72	A	433	433	433	433	1.067e+39 0.9	1.695e+38 0.1	1.237e+39 1.1
73	A	447	447	450	447	8.088e+38 0.7	6.051e+38 0.5	1.414e+39 1.2
74	B	451	453	451	451	1.463e+38 0.1	2.217e+38 0.2	3.680e+38 0.3
75	A	455	455	457	455	1.194e+39 1.0	7.088e+38 0.6	1.903e+39 1.6
76	B	461	472	461	462	4.411e+38 0.4	4.829e+38 0.4	9.240e+38 0.8
77	A	478	478	478	478	8.976e+39 7.7	1.073e+40 9.2	1.971e+40 16.8
78	B	480	480	480	480	5.539e+36 0.0	6.401e+36 0.0	1.194e+37 0.0
79	B	482	483	482	482	5.562e+38 0.5	6.012e+38 0.5	1.157e+39 1.0
80	A	488	488	488	488	4.353e+38 0.4	2.441e+38 0.2	6.794e+38 0.6
81	A	490	490	490	490	6.653e+38 0.6	5.612e+38 0.5	1.226e+39 1.0
82	B	494	494	494	494	1.551e+38 0.1	2.476e+38 0.2	4.027e+38 0.3
83	B	566	567	566	569	3.468e+38 0.3	3.793e+38 0.3	7.261e+38 0.6
84	A	570	570	570	570	7.372e+38 0.6	5.913e+38 0.5	1.329e+39 1.1
85	B	575	578	575	578	2.466e+38 0.2	3.120e+38 0.3	5.586e+38 0.5
86	A	578	579	584	581	1.833e+38 0.2	2.064e+38 0.2	3.897e+38 0.3
87	B	584	585	584	585	1.123e+39 1.0	1.197e+39 1.0	2.321e+39 2.0
88	A	585	585	585	585	7.031e+38 0.6	3.278e+38 0.3	1.031e+39 0.9
89	A	587	587	588	587	2.995e+38 0.3	3.292e+37 0.0	3.324e+38 0.3
90	A	590	590	594	590	1.124e+38 0.1	4.560e+37 0.0	1.580e+38 0.1
91	B	594	594	596	594	1.589e+38 0.1	1.776e+38 0.2	3.365e+38 0.3
92	B	596	596	597	596	4.394e+38 0.4	5.198e+38 0.4	9.592e+38 0.8
93	A	602	602	603	602	3.798e+39 3.2	2.847e+39 2.4	6.645e+39 5.7
94	B	603	603	604	603	5.250e+37 0.0	6.093e+37 0.1	1.134e+38 0.1
95	B	606	606	606	606	3.830e+39 3.3	4.076e+39 3.5	7.906e+39 6.7
96	A	608	608	608	608	1.958e+39 1.7	1.462e+39 1.2	3.420e+39 2.9
97	B	641	647	641	647	5.585e+37 0.0	8.795e+37 0.1	1.438e+38 0.1
98	A	647	649	647	648	1.002e+39 0.9	9.521e+38 0.8	1.955e+39 1.7
99	B	654	655	654	655	1.255e+39 1.1	2.103e+39 1.8	3.358e+39 2.9
100	A	655	655	656	655	5.952e+38 0.5	4.543e+38 0.4	1.049e+39 0.9
101	B	657	657	657	659	9.551e+37 0.1	1.556e+38 0.1	2.511e+38 0.2
102	A	659	659	659	659	6.185e+37 0.1	6.649e+37 0.1	1.283e+38 0.1
103	A	979	979	979	979	4.243e+39 3.6	4.558e+37 0.0	4.289e+39 3.7
104	B	979	980	979	979	1.539e+38 0.1	2.536e+38 0.2	4.075e+38 0.3
105	B	983	984	983	983	3.135e+37 0.0	4.703e+37 0.0	7.838e+37 0.1
106	A	984	985	985	984	2.718e+40 23.2	1.183e+38 0.1	2.730e+40 23.3
107	B	985	985	985	985	5.346e+37 0.0	5.735e+37 0.0	1.108e+38 0.1
108	A	989	989	989	989	1.171e+41 99.9	6.781e+37 0.1	1.172e+41 100.0
109	A	1054	1054	1054	1054	3.259e+39 2.8	2.083e+38 0.2	3.467e+39 3.0
110	B	1061	1063	1061	1063	3.130e+38 0.3	3.895e+38 0.3	7.025e+38 0.6
111	A	1063	1072	1079	1065	5.784e+38 0.5	1.089e+38 0.1	6.874e+38 0.6
112	B	1079	1081	1086	1083	5.708e+38 0.5	6.651e+38 0.6	1.236e+39 1.1
113	A	1093	1093	1094	1093	2.519e+39 2.2	1.460e+39 1.2	3.979e+39 3.4
114	B	1097	1103	1097	1098	1.648e+39 1.4	1.781e+39 1.5	3.429e+39 2.9
115	A	1111	1111	1111	1111	2.254e+39 1.9	1.933e+39 1.6	4.187e+39 3.6
116	B	1115	1118	1115	1125	5.724e+37 0.0	9.614e+37 0.1	1.534e+38 0.1
117	A	1126	1126	1126	1126	2.117e+39 1.8	1.011e+39 0.9	3.129e+39 2.7
118	B	1126	1135	1126	1127	1.331e+39 1.1	1.949e+39 1.7	3.280e+39 2.8
119	A	1135	1135	1138	1135	1.677e+39 1.4	1.109e+39 0.9	2.786e+39 2.4
120	B	1138	1139	1146	1144	3.439e+39 2.9	4.313e+39 3.7	7.753e+39 6.6
121	B	1146	1155	1155	1155	1.671e+39 1.4	1.995e+39 1.7	3.666e+39 3.1
122	A	1155	1163	1164	1163	4.107e+39 3.5	3.731e+39 3.2	7.838e+39 6.7
123	B	1164	1178	1180	1179	1.274e+38 0.1	1.679e+38 0.1	2.953e+38 0.3
124	B	1180	1196	1186	1196	3.461e+39 3.0	5.670e+39 4.8	9.132e+39 7.8
125	A	1196	1203	1201	1206	1.960e+39 1.7	6.740e+38 0.6	2.634e+39 2.2
126	A	1208	1208	1208	1208	8.283e+38 0.7	6.146e+38 0.5	1.443e+39 1.2
127	A	1517	1517	1520	1517	2.304e+38 0.2	1.590e+38 0.1	3.894e+38 0.3
128	B	1567	1570	1567	1570	2.357e+37 0.0	3.786e+37 0.0	6.144e+37 0.1
129	A	1570	1570	1571	1571	6.150e+38 0.5	3.081e+38 0.3	9.231e+38 0.8
130	B	3439	3440	3439	3441	2.307e+39 2.0	3.412e+39 2.9	5.719e+39 4.9
131	A	3441	3441	3450	3441	2.819e+40 24.1	4.242e+39 3.6	3.243e+40 27.7
132	A	3527	3527	3529	3527	1.600e+40 13.7	2.018e+39 1.7	1.802e+40 15.4
133	A	3581	3581	3583	3581	1.370e+40 11.7	4.225e+39 3.6	1.793e+40 15.3
134	B	3583	3585	3585	3583	2.767e+39 2.4	4.669e+39 4.0	7.435e+39 6.3
135	B	3609	3610	3609	3613	3.855e+39 3.3	6.019e+39 5.1	9.875e+39 8.4

No.

Char.

ω TO

ω LOx

ω LOy

ω LOz

I ∥

I ⊥