- JAFFEITE - Ca₆Si₂O₇(OH)₆

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:	143		P3
Lattice parameters (Å):	10.0350	10.0350		7.4990
Angles (°):	90	90		120

Symmetry (theoretical):

Space group:	143		P3
Lattice parameters (Å):	10.0364	10.0364		7.4969
Angles (°):	90	90		120

Cell contents:

Number of atoms:	54
Number of atom types:	4
Chemical composition:	0

Atomic positions (theoretical):

Ca:	0.6684	0.0439	0.9928
Ca:	0.6632	0.0498	0.4987
Ca:	0.0498	0.3866	0.2421
Ca:	0.0439	0.3756	0.7480
Si:	0.6667	0.3333	0.7127
Si:	0.6667	0.3333	0.2762
Si:	0.3333	0.6667	0.0280
Si:	0.3333	0.6667	0.4645
O:	0.6667	0.3333	0.4946
O:	0.3333	0.6667	0.2461
O:	0.5968	0.1540	0.2266
O:	0.5968	0.1545	0.7629
O:	0.1545	0.5578	0.9778
O:	0.1540	0.5572	0.5141
O:	0.2163	0.2878	0.2509
O:	0.2069	0.2713	0.7404
O:	0.9357	0.2070	0.0005
O:	0.9285	0.2163	0.4900
H:	0.1718	0.1619	0.7412
H:	0.1620	0.9901	0.9993
H:	0.1785	0.9962	0.4905
H:	0.1821	0.1785	0.2505
Ca:	0.3755	0.3316	0.9928
Ca:	0.3865	0.3368	0.4987
Ca:	0.3368	0.9502	0.2421
Ca:	0.3317	0.9561	0.7480
O:	0.5572	0.4032	0.2266
O:	0.5577	0.4032	0.7629
O:	0.4033	0.8455	0.9778
O:	0.4032	0.8460	0.5141
O:	0.0715	0.7837	0.2509
O:	0.0644	0.7931	0.7404
O:	0.2713	0.0643	0.0005
O:	0.2878	0.0715	0.4900
H:	0.9901	0.8282	0.7412
H:	0.8282	0.8380	0.9993
H:	0.8178	0.8215	0.4905
H:	0.9964	0.8179	0.2505
Ca:	0.9561	0.6245	0.9928
Ca:	0.9502	0.6135	0.4987
Ca:	0.6134	0.6632	0.2421
Ca:	0.6244	0.6683	0.7480
O:	0.8460	0.4428	0.2266
O:	0.8455	0.4423	0.7629
O:	0.4422	0.5967	0.9778
O:	0.4428	0.5968	0.5141
O:	0.7122	0.9285	0.2509
O:	0.7287	0.9356	0.7404
O:	0.7930	0.7287	0.0005
O:	0.7837	0.7122	0.4900
H:	0.8381	0.0099	0.7412
H:	0.0099	0.1718	0.9993
H:	0.0038	0.1822	0.4905
H:	0.8215	0.0036	0.2505

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.

Dielectric Properties

We define:

The Born effective charges, also called dynamical charges, are tensors that correspond to the energy derivative with respect to atomic displacements and electric fields or, equivalently, to the change in atomic force due to an electric field: The sum of the Born effective charges of all nuclei in one cell must vanish, element by element, along each of the three directions of the space.
The dielectric tensors are the energy derivative with respect to two electric fields. They also relate the induced polarization to the external electric field.

Born effective charges (Z):

Ca:	2.1702	0.0754	-0.0037
	0.0247	2.1666	-0.0071
	-0.0152	-0.0254	2.2889
Eig. Value:	2.2141	2.1182	2.2934
Ca:	2.1544	0.0075	0.0028
	-0.0021	2.2787	0.0018
	0.0140	0.0229	2.1420
Eig. Value:	2.1581	2.2799	2.1371
Ca:	2.2501	0.0572	-0.0026
	0.0479	2.1830	0.0015
	-0.0264	0.0009	2.1423
Eig. Value:	2.2799	2.1580	2.1374
Ca:	2.2107	-0.0013	0.0080
	-0.0521	2.1262	0.0008
	0.0295	0.0001	2.2887
Eig. Value:	2.2142	2.1183	2.2931
Si:	2.8558	-0.0268	-0.0000
	0.0268	2.8558	0.0000
	0.0000	-0.0000	2.9087
Eig. Value:	2.8558	2.8558	2.9087
Si:	2.9096	0.0029	0.0000
	-0.0029	2.9096	-0.0000
	-0.0000	0.0000	2.8938
Eig. Value:	2.9096	2.9096	2.8938
Si:	2.8556	-0.0270	-0.0000
	0.0270	2.8556	-0.0000
	0.0000	0.0000	2.9088
Eig. Value:	2.8556	2.8556	2.9088
Si:	2.9097	0.0028	-0.0000
	-0.0028	2.9097	-0.0000
	0.0000	0.0000	2.8938
Eig. Value:	2.9097	2.9097	2.8938
O:	-1.1762	0.0045	0.0000
	-0.0045	-1.1762	-0.0000
	0.0000	0.0000	-3.0863
Eig. Value:	-1.1762	-1.1762	-3.0863
O:	-1.1762	0.0045	0.0000
	-0.0045	-1.1762	-0.0000
	-0.0000	0.0000	-3.0864
Eig. Value:	-1.1762	-1.1762	-3.0864
O:	-1.4527	0.0808	0.0510
	0.0797	-2.3748	-0.1451
	0.0559	-0.2902	-1.5427
Eig. Value:	-1.4272	-2.4367	-1.5063
O:	-1.4618	0.0945	-0.0525
	0.0882	-2.2828	0.1555
	-0.0549	0.2913	-1.5730
Eig. Value:	-1.4400	-2.3590	-1.5185
O:	-1.9992	-0.3978	-0.1084
	-0.4043	-1.7454	-0.1234
	-0.2249	-0.1933	-1.5729
Eig. Value:	-2.3591	-1.4398	-1.5185
O:	-2.0747	-0.4387	0.1004
	-0.4400	-1.7529	0.1167
	0.2235	0.1933	-1.5428
Eig. Value:	-2.4366	-1.4275	-1.5062
O:	-1.6476	0.0448	-0.0110
	0.0665	-1.0927	-0.0080
	-0.0295	-0.0083	-1.5260
Eig. Value:	-1.6560	-1.0870	-1.5234
O:	-1.6399	0.0214	0.0099
	0.0404	-1.0468	0.0113
	0.0281	0.0125	-1.5557
Eig. Value:	-1.6453	-1.0449	-1.5522
O:	-1.2219	-0.2819	0.0047
	-0.2629	-1.4646	-0.0140
	-0.0031	-0.0305	-1.5557
Eig. Value:	-1.0448	-1.6452	-1.5523
O:	-1.2800	-0.2789	-0.0017
	-0.2567	-1.4612	0.0138
	0.0074	0.0298	-1.5258
Eig. Value:	-1.0876	-1.6562	-1.5231
H:	0.4223	-0.0546	-0.0029
	-0.0466	0.1533	-0.0095
	-0.0046	-0.0058	0.4290
Eig. Value:	0.4330	0.1439	0.4278
H:	0.1766	-0.0951	0.0094
	-0.0872	0.3988	0.0027
	0.0073	-0.0006	0.4292
Eig. Value:	0.1437	0.4325	0.4283
H:	0.1731	-0.0802	-0.0111
	-0.0743	0.4218	-0.0011
	-0.0092	0.0021	0.4318
Eig. Value:	0.1507	0.4447	0.4313
H:	0.4266	-0.0720	0.0046
	-0.0661	0.1680	0.0100
	0.0065	0.0068	0.4317
Eig. Value:	0.4447	0.1504	0.4311
Ca:	2.1242	0.0019	-0.0043
	-0.0488	2.2126	0.0067
	-0.0144	0.0259	2.2889
Eig. Value:	2.1182	2.2141	2.2934
Ca:	2.2453	-0.0504	0.0001
	-0.0600	2.1878	-0.0033
	0.0128	-0.0235	2.1420
Eig. Value:	2.2799	2.1581	2.1371
Ca:	2.1542	0.0075	0.0026
	-0.0019	2.2788	0.0015
	0.0140	0.0225	2.1423
Eig. Value:	2.1580	2.2799	2.1374
Ca:	2.1704	0.0753	-0.0033
	0.0245	2.1665	-0.0073
	-0.0146	-0.0256	2.2887
Eig. Value:	2.2142	2.1183	2.2931
O:	-2.2138	0.3597	-0.1512
	0.3586	-1.6138	0.0284
	-0.2792	0.0967	-1.5427
Eig. Value:	-2.4367	-1.4272	-1.5063
O:	-2.1567	0.3130	0.1610
	0.3067	-1.5879	-0.0323
	0.2797	-0.0981	-1.5730
Eig. Value:	-2.3590	-1.4400	-1.5185
O:	-1.4616	0.0939	-0.0526
	0.0874	-2.2830	0.1556
	-0.0549	0.2914	-1.5729
Eig. Value:	-1.4398	-2.3591	-1.5185
O:	-1.4529	0.0809	0.0509
	0.0796	-2.3747	-0.1452
	0.0557	-0.2902	-1.5428
Eig. Value:	-1.4275	-2.4366	-1.5062
O:	-1.2796	-0.2790	-0.0015
	-0.2572	-1.4607	0.0135
	0.0076	0.0297	-1.5260
Eig. Value:	-1.0870	-1.6560	-1.5234
O:	-1.2219	-0.2818	0.0048
	-0.2628	-1.4648	-0.0143
	-0.0032	-0.0306	-1.5557
Eig. Value:	-1.0449	-1.6453	-1.5522
O:	-1.1680	0.2318	-0.0145
	0.2507	-1.5185	0.0029
	-0.0249	0.0179	-1.5557
Eig. Value:	-1.0448	-1.6452	-1.5523
O:	-1.1840	0.2013	0.0128
	0.2235	-1.5572	-0.0055
	0.0221	-0.0213	-1.5258
Eig. Value:	-1.0876	-1.6562	-1.5231
H:	0.2643	0.1378	-0.0068
	0.1458	0.3113	0.0073
	-0.0027	0.0069	0.4290
Eig. Value:	0.1439	0.4330	0.4278
H:	0.4222	-0.0546	-0.0024
	-0.0467	0.1532	-0.0094
	-0.0042	-0.0061	0.4292
Eig. Value:	0.4325	0.1437	0.4283
H:	0.4265	-0.0720	0.0045
	-0.0661	0.1683	0.0101
	0.0064	0.0069	0.4318
Eig. Value:	0.4447	0.1507	0.4313
H:	0.2924	0.1435	0.0064
	0.1495	0.3021	-0.0090
	0.0026	-0.0090	0.4317
Eig. Value:	0.1504	0.4447	0.4311
Ca:	2.2108	-0.0012	0.0080
	-0.0519	2.1260	0.0004
	0.0296	-0.0005	2.2889
Eig. Value:	2.2141	2.1182	2.2934
Ca:	2.2499	0.0573	-0.0029
	0.0477	2.1831	0.0015
	-0.0268	0.0007	2.1420
Eig. Value:	2.2799	2.1581	2.1371
Ca:	2.2453	-0.0506	0.0000
	-0.0600	2.1878	-0.0030
	0.0125	-0.0233	2.1423
Eig. Value:	2.2799	2.1580	2.1374
Ca:	2.1242	0.0022	-0.0047
	-0.0487	2.2127	0.0065
	-0.0149	0.0255	2.2887
Eig. Value:	2.1183	2.2142	2.2931
O:	-2.0748	-0.4388	0.1001
	-0.4400	-1.7527	0.1167
	0.2234	0.1935	-1.5427
Eig. Value:	-2.4367	-1.4272	-1.5063
O:	-1.9984	-0.3981	-0.1084
	-0.4044	-1.7462	-0.1233
	-0.2248	-0.1932	-1.5730
Eig. Value:	-2.3590	-1.4400	-1.5185
O:	-2.1562	0.3136	0.1611
	0.3071	-1.5884	-0.0322
	0.2799	-0.0981	-1.5729
Eig. Value:	-2.3591	-1.4398	-1.5185
O:	-2.2138	0.3597	-0.1512
	0.3584	-1.6138	0.0286
	-0.2792	0.0969	-1.5428
Eig. Value:	-2.4366	-1.4275	-1.5062
O:	-1.1833	0.2016	0.0125
	0.2233	-1.5571	-0.0055
	0.0219	-0.0214	-1.5260
Eig. Value:	-1.0870	-1.6560	-1.5234
O:	-1.1683	0.2318	-0.0148
	0.2509	-1.5184	0.0029
	-0.0248	0.0181	-1.5557
Eig. Value:	-1.0449	-1.6453	-1.5522
O:	-1.6399	0.0217	0.0097
	0.0406	-1.0467	0.0111
	0.0280	0.0126	-1.5557
Eig. Value:	-1.6452	-1.0448	-1.5523
O:	-1.6478	0.0444	-0.0111
	0.0665	-1.0934	-0.0083
	-0.0295	-0.0085	-1.5258
Eig. Value:	-1.6562	-1.0876	-1.5231
H:	0.1767	-0.0952	0.0097
	-0.0872	0.3989	0.0023
	0.0074	-0.0011	0.4290
Eig. Value:	0.1439	0.4330	0.4278
H:	0.2643	0.1378	-0.0070
	0.1458	0.3111	0.0068
	-0.0032	0.0066	0.4292
Eig. Value:	0.1437	0.4325	0.4283
H:	0.2927	0.1434	0.0065
	0.1493	0.3022	-0.0090
	0.0028	-0.0090	0.4318
Eig. Value:	0.1507	0.4447	0.4313
H:	0.1728	-0.0804	-0.0110
	-0.0745	0.4217	-0.0011
	-0.0091	0.0022	0.4317
Eig. Value:	0.1504	0.4447	0.4311