- BARBERIITE - NH₄BF₄

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:	62		Pbnm
Lattice parameters (Å):	7.2430	8.8080		5.9080
Angles (°):	90.0	90.0		90.0

Symmetry (theoretical):

Space group:	62		Pbnm
Lattice parameters (Å):	6.7441	8.0595		5.8772
Angles (°):	90.0	90.0		90.0

Cell contents:

Number of atoms:	40
Number of atom types:	4
Chemical composition:	0

Atomic positions (theoretical):

N:	0.1867	0.1790	0.2500
H:	0.0943	0.2809	0.2500
H:	0.3333	0.2173	0.2500
H:	0.1608	0.1069	0.1075
B:	0.6938	0.0865	0.2500
F:	0.5583	0.9566	0.2500
F:	0.5915	0.2372	0.2500
F:	0.8134	0.0782	0.0571
N:	0.6867	0.3210	0.7500
H:	0.5943	0.2191	0.7500
H:	0.8333	0.2827	0.7500
H:	0.6608	0.3931	0.8925
B:	0.1938	0.4135	0.7500
F:	0.0583	0.5434	0.7500
F:	0.0915	0.2628	0.7500
F:	0.3134	0.4218	0.9429
N:	0.8133	0.8210	0.7500
H:	0.9057	0.7191	0.7500
H:	0.6667	0.7827	0.7500
H:	0.8392	0.8931	0.6075
B:	0.3062	0.9135	0.7500
F:	0.4417	0.0434	0.7500
F:	0.4085	0.7628	0.7500
F:	0.1866	0.9218	0.5571
N:	0.3133	0.6790	0.2500
H:	0.4057	0.7809	0.2500
H:	0.1667	0.7173	0.2500
H:	0.3392	0.6069	0.3925
B:	0.8062	0.5865	0.2500
F:	0.9417	0.4566	0.2500
F:	0.9085	0.7372	0.2500
F:	0.6866	0.5782	0.4429
H:	0.8392	0.8931	0.8925
F:	0.1866	0.9218	0.9429
H:	0.3392	0.6069	0.1075
F:	0.6866	0.5782	0.0571
H:	0.1608	0.1069	0.3925
F:	0.8134	0.0782	0.4429
F:	0.6608	0.3931	0.6075
F:	0.3134	0.4218	0.5571

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):

N:	-0.6801	0.0584	0.0000
	0.0453	-0.6713	0.0000
	0.0000	0.0000	-0.6079
Eig. Value:	-0.7277	-0.6237	-0.6079
H:	0.4971	-0.2544	-0.0000
	-0.2401	0.6582	-0.0000
	0.0000	-0.0000	0.3044
Eig. Value:	0.3176	0.8377	0.3044
H:	0.8789	0.0685	0.0000
	0.0096	0.3233	-0.0000
	0.0000	-0.0000	0.3190
Eig. Value:	0.8817	0.3205	0.3190
H:	0.3491	-0.0361	-0.0090
	0.0056	0.5716	0.2244
	0.0023	0.2689	0.5801
Eig. Value:	0.3519	0.3260	0.8229
B:	2.3461	-0.0627	0.0000
	-0.0051	2.2645	0.0000
	-0.0000	-0.0000	2.3626
Eig. Value:	2.3584	2.2522	2.3626
F:	-1.0000	-0.4704	-0.0000
	-0.4763	-1.1697	0.0000
	0.0000	0.0000	-0.5726
Eig. Value:	-0.6040	-1.5658	-0.5726
F:	-1.0420	0.3025	0.0000
	0.2887	-1.0949	0.0000
	0.0000	0.0000	-0.6155
Eig. Value:	-0.7717	-1.3652	-0.6155
F:	-0.8492	0.0521	0.3399
	0.0335	-0.7266	-0.1078
	0.3452	-0.1668	-1.1751
Eig. Value:	-0.6166	-0.7149	-1.4194
N:	-0.6801	-0.0584	0.0000
	-0.0453	-0.6713	-0.0000
	0.0000	-0.0000	-0.6079
Eig. Value:	-0.7277	-0.6237	-0.6079
H:	0.4971	0.2544	-0.0000
	0.2401	0.6582	0.0000
	0.0000	0.0000	0.3044
Eig. Value:	0.3176	0.8377	0.3044
H:	0.8789	-0.0685	0.0000
	-0.0096	0.3233	0.0000
	0.0000	0.0000	0.3190
Eig. Value:	0.8817	0.3205	0.3190
H:	0.3491	0.0361	0.0090
	-0.0056	0.5716	0.2244
	-0.0023	0.2689	0.5801
Eig. Value:	0.3519	0.3260	0.8229
B:	2.3461	0.0627	0.0000
	0.0051	2.2645	-0.0000
	0.0000	0.0000	2.3626
Eig. Value:	2.3584	2.2522	2.3626
F:	-1.0000	0.4704	-0.0000
	0.4763	-1.1697	-0.0000
	0.0000	-0.0000	-0.5726
Eig. Value:	-0.6040	-1.5658	-0.5726
F:	-1.0420	-0.3025	0.0000
	-0.2887	-1.0949	-0.0000
	0.0000	-0.0000	-0.6155
Eig. Value:	-0.7717	-1.3652	-0.6155
F:	-0.8492	-0.0521	-0.3399
	-0.0335	-0.7266	-0.1078
	-0.3452	-0.1668	-1.1751
Eig. Value:	-0.6166	-0.7149	-1.4194
N:	-0.6801	0.0584	-0.0000
	0.0453	-0.6713	-0.0000
	-0.0000	-0.0000	-0.6079
Eig. Value:	-0.7277	-0.6237	-0.6079
H:	0.4971	-0.2544	0.0000
	-0.2401	0.6582	-0.0000
	-0.0000	0.0000	0.3044
Eig. Value:	0.3176	0.8377	0.3044
H:	0.8789	0.0685	-0.0000
	0.0096	0.3233	0.0000
	-0.0000	0.0000	0.3190
Eig. Value:	0.8817	0.3205	0.3190
H:	0.3491	-0.0361	0.0090
	0.0056	0.5716	-0.2244
	-0.0023	-0.2689	0.5801
Eig. Value:	0.3519	0.3260	0.8229
B:	2.3461	-0.0627	-0.0000
	-0.0051	2.2645	-0.0000
	-0.0000	0.0000	2.3626
Eig. Value:	2.3584	2.2522	2.3626
F:	-1.0000	-0.4704	0.0000
	-0.4763	-1.1697	-0.0000
	-0.0000	-0.0000	-0.5726
Eig. Value:	-0.6040	-1.5658	-0.5726
F:	-1.0420	0.3025	-0.0000
	0.2887	-1.0949	-0.0000
	-0.0000	-0.0000	-0.6155
Eig. Value:	-0.7717	-1.3652	-0.6155
F:	-0.8492	0.0521	-0.3399
	0.0335	-0.7266	0.1078
	-0.3452	0.1668	-1.1751
Eig. Value:	-0.6166	-0.7149	-1.4194
N:	-0.6801	-0.0584	0.0000
	-0.0453	-0.6713	0.0000
	-0.0000	0.0000	-0.6079
Eig. Value:	-0.7277	-0.6237	-0.6079
H:	0.4971	0.2544	0.0000
	0.2401	0.6582	0.0000
	-0.0000	-0.0000	0.3044
Eig. Value:	0.3176	0.8377	0.3044
H:	0.8789	-0.0685	-0.0000
	-0.0096	0.3233	-0.0000
	-0.0000	-0.0000	0.3190
Eig. Value:	0.8817	0.3205	0.3190
H:	0.3491	0.0361	-0.0090
	-0.0056	0.5716	-0.2244
	0.0023	-0.2689	0.5801
Eig. Value:	0.3519	0.3260	0.8229
B:	2.3461	0.0627	-0.0000
	0.0051	2.2645	0.0000
	0.0000	-0.0000	2.3626
Eig. Value:	2.3584	2.2522	2.3626
F:	-1.0000	0.4704	0.0000
	0.4763	-1.1697	0.0000
	-0.0000	0.0000	-0.5726
Eig. Value:	-0.6040	-1.5658	-0.5726
F:	-1.0420	-0.3025	-0.0000
	-0.2887	-1.0949	-0.0000
	-0.0000	0.0000	-0.6155
Eig. Value:	-0.7717	-1.3652	-0.6155
F:	-0.8492	-0.0521	0.3399
	-0.0335	-0.7266	0.1078
	0.3452	0.1668	-1.1751
Eig. Value:	-0.6166	-0.7149	-1.4194
H:	0.3491	-0.0361	-0.0090
	0.0056	0.5716	0.2244
	0.0023	0.2689	0.5801
Eig. Value:	0.3519	0.3260	0.8229
F:	-0.8492	0.0521	0.3399
	0.0335	-0.7266	-0.1078
	0.3452	-0.1668	-1.1751
Eig. Value:	-0.6166	-0.7149	-1.4194
H:	0.3491	0.0361	0.0090
	-0.0056	0.5716	0.2244
	-0.0023	0.2689	0.5801
Eig. Value:	0.3519	0.3260	0.8229
F:	-0.8492	-0.0521	-0.3399
	-0.0335	-0.7266	-0.1078
	-0.3452	-0.1668	-1.1751
Eig. Value:	-0.6166	-0.7149	-1.4194
H:	0.3491	-0.0361	0.0090
	0.0056	0.5716	-0.2244
	-0.0023	-0.2689	0.5801
Eig. Value:	0.3519	0.3260	0.8229
F:	-0.8492	0.0521	-0.3399
	0.0335	-0.7266	0.1078
	-0.3452	0.1668	-1.1751
Eig. Value:	-0.6166	-0.7149	-1.4194
F:	0.3491	0.0361	-0.0090
	-0.0056	0.5716	-0.2244
	0.0023	-0.2689	0.5801
Eig. Value:	0.3519	0.3260	0.8229
F:	-0.8492	-0.0521	0.3399
	-0.0335	-0.7266	0.1078
	0.3452	0.1668	-1.1751
Eig. Value:	-0.6166	-0.7149	-1.4194

Atom type

Dielectric tensors:

	X	Y	Z
Ɛ_∞:	2.0371	0.0000	0.0000
	0.0000	2.0392	0.0000
	0.0000	0.0000	2.0109
Eig. Value:	2.0371	2.0392	2.0109
Refractive index (N):	1.4273	-0.0000	-0.0000
	-0.0000	1.4280	-0.0000
	-0.0000	-0.0000	1.4181
Eig. Value:	1.4273	1.4280	1.4181
Ɛ₀:	0.0000	0.0000	0.0000
	0.0000	0.0000	0.0000
	0.0000	0.0000	0.0000
Eig. Value:	0.0000	0.0000	0.0000

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	45	45	45	45
5	Au	61	61	61	61
6	B1u	62	62	62	62
7	B3g	62	62	62	65	3.880e+37 0.0	5.336e+37 0.1	9.216e+37 0.1
8	B3g	65	65	65	67	2.405e+38 0.3	3.306e+38 0.4	5.711e+38 0.7
9	B2u	67	67	69	69
10	A1g	77	77	77	77	1.428e+38 0.2	1.009e+38 0.1	2.438e+38 0.3
11	B1g	79	79	79	79	4.404e+38 0.5	6.056e+38 0.7	1.046e+39 1.2
12	B2g	81	81	81	81	1.667e+38 0.2	2.293e+38 0.3	3.960e+38 0.5
13	A1g	81	81	81	81	4.791e+38 0.6	3.366e+38 0.4	8.157e+38 0.9
14	B3g	86	86	86	86	1.689e+38 0.2	2.323e+38 0.3	4.012e+38 0.5
15	B3u	88	89	88	88
16	B1g	89	93	89	89	3.030e+36 0.0	4.166e+36 0.0	7.196e+36 0.0
17	B1u	94	94	94	94
18	B3g	98	98	98	98	7.277e+37 0.1	1.001e+38 0.1	1.728e+38 0.2
19	Au	108	108	108	108
20	B2g	114	114	114	114	1.144e+38 0.1	1.573e+38 0.2	2.717e+38 0.3
21	B2u	115	115	116	115
22	A1g	123	123	123	123	5.005e+38 0.6	2.344e+37 0.0	5.240e+38 0.6
23	B1g	125	125	125	125	7.007e+36 0.0	9.635e+36 0.0	1.664e+37 0.0
24	B3u	144	145	144	144
25	B2g	191	191	191	191	7.369e+37 0.1	1.013e+38 0.1	1.750e+38 0.2
26	A1g	201	201	201	201	5.487e+38 0.6	3.598e+38 0.4	9.086e+38 1.1
27	Au	202	202	202	202
28	B3g	215	215	215	215	1.515e+38 0.2	2.083e+38 0.2	3.598e+38 0.4
29	B1u	216	216	216	223
30	B2u	223	223	223	233
31	B3u	233	240	233	242
32	B1g	242	242	242	243	1.534e+37 0.0	2.109e+37 0.0	3.643e+37 0.0
33	B3u	243	243	243	243
34	Ag	243	245	243	245	1.927e+38 0.2	1.194e+38 0.1	3.121e+38 0.4
35	B2u	245	251	251	247
36	B2g	251	260	260	251	1.058e+39 1.2	1.455e+39 1.7	2.513e+39 2.9
37	Au	260	262	262	260
38	Au	262	262	262	262	6.581e+36 0.0	9.049e+36 0.0	1.563e+37 0.0
39	B2u	262	274	274	274	8.209e+39 9.5	1.129e+40 13.1	1.950e+40 22.7
40	B1g	274	302	312	293	1.958e+37 0.0	2.692e+37 0.0	4.650e+37 0.1
41	B1g	329	329	329	329	4.845e+37 0.1	6.662e+37 0.1	1.151e+38 0.1
42	Au	332	332	332	332
43	B2g	333	333	333	333	2.601e+37 0.0	3.577e+37 0.0	6.178e+37 0.1
44	B1u	336	336	336	336
45	A1g	336	336	336	336	5.448e+39 6.3	4.079e+39 4.7	9.528e+39 11.1
46	B3g	339	339	339	339	1.436e+39 1.7	1.974e+39 2.3	3.410e+39 4.0
47	B2u	348	348	348	348
48	B3u	348	353	348	348
49	B3u	357	358	357	357
50	A1g	362	362	362	362	9.332e+37 0.1	6.857e+37 0.1	1.619e+38 0.2
51	B2u	365	365	366	365
52	B1u	367	367	367	369
53	Au	372	372	372	372
54	B1g	376	376	376	376	1.752e+37 0.0	2.410e+37 0.0	4.162e+37 0.0
55	B3g	380	380	380	380	1.127e+38 0.1	1.397e+38 0.2	2.524e+38 0.3
56	B3g	380	380	380	380	7.244e+38 0.8	1.011e+39 1.2	1.736e+39 2.0
57	Au	498	498	498	498
58	B1u	502	502	502	502
59	B3u	504	505	504	504
60	B2g	505	505	505	505	4.822e+38 0.6	6.630e+38 0.8	1.145e+39 1.3
61	Ag	505	505	505	505	1.888e+38 0.2	1.717e+38 0.2	3.605e+38 0.4
62	B1g	505	505	505	505	1.870e+38 0.2	1.712e+38 0.2	3.582e+38 0.4
63	B2u	506	506	507	506
64	B3g	507	507	508	507	1.591e+38 0.2	2.188e+38 0.3	3.779e+38 0.4
65	A1g	527	527	527	527	6.481e+38 0.8	4.512e+38 0.5	1.099e+39 1.3
66	B2u	527	527	528	527
67	B1g	529	529	529	529	1.084e+39 1.3	1.490e+39 1.7	2.574e+39 3.0
68	B3u	530	531	530	530
69	B2u	765	765	766	765
70	B3u	767	767	767	767
71	Ag	767	767	767	767	1.149e+40 13.4	8.680e+37 0.1	1.158e+40 13.5
72	B1g	767	767	767	767	1.355e+40 15.8	7.927e+37 0.1	1.363e+40 15.9
73	A1g	1011	1011	1011	1011	2.966e+38 0.3	2.122e+38 0.2	5.088e+38 0.6
74	B2u	1025	1025	1028	1025
75	Au	1028	1028	1039	1028
76	B1u	1039	1039	1041	1041
77	B3u	1041	1043	1042	1043
78	B2u	1043	1050	1050	1050
79	B2g	1050	1054	1054	1054	1.930e+38 0.2	2.653e+38 0.3	4.583e+38 0.5
80	A1g	1054	1064	1064	1064	5.713e+38 0.7	3.659e+38 0.4	9.372e+38 1.1
81	B3g	1064	1070	1070	1070	2.420e+38 0.3	3.328e+38 0.4	5.748e+38 0.7
82	B1g	1070	1084	1086	1086	7.682e+38 0.9	1.056e+39 1.2	1.824e+39 2.1
83	B3u	1086	1094	1094	1094
84	B1g	1094	1143	1113	1134	1.356e+38 0.2	1.865e+38 0.2	3.222e+38 0.4
85	B1u	1383	1383	1383	1395
86	B1g	1395	1395	1395	1398	3.770e+38 0.4	5.184e+38 0.6	8.954e+38 1.0
87	B3u	1398	1398	1398	1398
88	B3g	1398	1400	1398	1400	2.033e+39 2.4	2.795e+39 3.3	4.829e+39 5.6
89	A1g	1400	1401	1400	1401	1.758e+39 2.0	1.316e+39 1.5	3.074e+39 3.6
90	B2g	1401	1411	1401	1403	7.880e+35 0.0	1.084e+36 0.0	1.872e+36 0.0
91	A1g	1411	1415	1411	1411	2.380e+38 0.3	7.827e+37 0.1	3.163e+38 0.4
92	Au	1415	1415	1415	1415
93	B2u	1417	1417	1425	1417
94	B2u	1431	1431	1448	1431
95	B3u	1448	1452	1452	1448
96	B1g	1452	1456	1456	1452	2.552e+36 0.0	3.509e+36 0.0	6.062e+36 0.0
97	B3g	1625	1625	1625	1625	8.950e+38 1.0	1.231e+39 1.4	2.126e+39 2.5
98	Au	1632	1632	1632	1632
99	B2g	1645	1645	1645	1645	1.228e+39 1.4	1.689e+39 2.0	2.917e+39 3.4
100	B1g	1648	1648	1648	1648	4.630e+38 0.5	6.366e+38 0.7	1.100e+39 1.3
101	B1u	1651	1651	1651	1652
102	B3u	1665	1665	1665	1665
103	B2u	1671	1671	1671	1671
104	A1g	1678	1678	1678	1678	1.465e+39 1.7	1.089e+39 1.3	2.555e+39 3.0
105	A1g	3177	3177	3177	3177	8.354e+40 97.2	2.444e+39 2.8	8.599e+40 100.0
106	B3u	3179	3184	3179	3179
107	B2u	3184	3186	3185	3184
108	B1g	3186	3192	3186	3186	3.570e+37 0.0	4.909e+37 0.1	8.480e+37 0.1
109	A1g	3216	3216	3216	3216	3.383e+40 39.3	9.752e+39 11.3	4.358e+40 50.7
110	B2u	3226	3226	3228	3226
111	B1g	3228	3228	3230	3228	1.645e+39 1.9	2.262e+39 2.6	3.907e+39 4.5
112	B1u	3231	3231	3231	3232
113	Au	3232	3232	3232	3237
114	B3u	3237	3241	3237	3241
115	B3g	3241	3242	3241	3242	1.520e+40 17.7	2.090e+40 24.3	3.610e+40 42.0
116	B2g	3242	3246	3242	3267	7.422e+37 0.1	1.021e+38 0.1	1.763e+38 0.2
117	B3u	3276	3278	3276	3276
118	A1g	3278	3283	3278	3278	7.651e+39 8.9	3.206e+39 3.7	1.086e+40 12.6
119	B2u	3283	3296	3296	3283
120	B1g	3296	3301	3323	3296	6.808e+39 7.9	9.361e+39 10.9	1.617e+40 18.8

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.

Normalized

Raw

Options for intensity.

Single Crystal Raman spectra

Single crystal Raman spectrum

The Raman measurements performed on single crystals employ polarized lasers and allow for the selection of specific elements of the individual Raman tensors of the Raman-active modes.

By convention, in the following we assume a measurement as X(XZ)Z, i.e. incident laser polarized along the X axis, emergent light polarized along the Z axis. If the crystal is aligned with the xyz reference frame, we sample the α_xz element. As you rotate the crystal you can sample other entries of the Raman tensor or various linear combineations.