I have some confusion. Can you please help me? There are some cubic perovskite structure whose CIF file are not included in material project website. For this type of materials how can i perform calculation by quantum espresso, how can i produce scf.in file? Example : SnGeBr3 cubic has CIF file but CsGeCl3 cubic has no CIF file in the website. Now if i want to perform calculation for cubic CsGeCl3 perovskite, What should i do?
1 Answer
You have two options:
- Search for other databases like ICSD-Inorganic Crystal Structure Database.
- Try to generate/predict the crystal structure yourself using software like USPEX.
Below is a CIF downloaded from ICSD database.
#(C) 2023 by FIZ Karlsruhe - Leibniz Institute for Information Infrastructure. All rights reserved.
data_23122-ICSD
_database_code_ICSD 23122
_audit_creation_date 1986-10-14
_audit_update_record 2003-04-01
_chemical_name_common 'Cesium trichlorogermanate(II) - HT'
_chemical_formula_structural 'Cs (Ge Cl3)'
_chemical_formula_sum 'Cl3 Cs1 Ge1'
_chemical_name_structure_type Perovskite#CaTiO3
_exptl_crystal_density_diffrn 3.16
_diffrn_ambient_temperature 453.
_citation_title
'A ferroelectric chloride of perowskite type. Crystal structures of Cs Ge Cl3'
loop_
_citation_id
_citation_journal_full
_citation_year
_citation_journal_volume
_citation_page_first
_citation_page_last
_citation_journal_id_ASTM
primary 'Acta Chemica Scandinavica ' 1965 19 421 428 ACSAA4
loop_
_citation_author_citation_id
_citation_author_name
primary 'Christensen, A.N.'
primary 'Rasmussen, S.E.'
_cell_length_a 5.475
_cell_length_b 5.475
_cell_length_c 5.475
_cell_angle_alpha 90.
_cell_angle_beta 90.
_cell_angle_gamma 90.
_cell_volume 164.12
_cell_formula_units_Z 1
_space_group_name_H-M_alt 'P m -3 m'
_space_group_IT_number 221
loop_
_space_group_symop_id
_space_group_symop_operation_xyz
1 'z, y, -x'
2 'y, x, -z'
3 'x, z, -y'
4 'z, x, -y'
5 'y, z, -x'
6 'x, y, -z'
7 'z, -y, x'
8 'y, -x, z'
9 'x, -z, y'
10 'z, -x, y'
11 'y, -z, x'
12 'x, -y, z'
13 '-z, y, x'
14 '-y, x, z'
15 '-x, z, y'
16 '-z, x, y'
17 '-y, z, x'
18 '-x, y, z'
19 '-z, -y, -x'
20 '-y, -x, -z'
21 '-x, -z, -y'
22 '-z, -x, -y'
23 '-y, -z, -x'
24 '-x, -y, -z'
25 '-z, -y, x'
26 '-y, -x, z'
27 '-x, -z, y'
28 '-z, -x, y'
29 '-y, -z, x'
30 '-x, -y, z'
31 '-z, y, -x'
32 '-y, x, -z'
33 '-x, z, -y'
34 '-z, x, -y'
35 '-y, z, -x'
36 '-x, y, -z'
37 'z, -y, -x'
38 'y, -x, -z'
39 'x, -z, -y'
40 'z, -x, -y'
41 'y, -z, -x'
42 'x, -y, -z'
43 'z, y, x'
44 'y, x, z'
45 'x, z, y'
46 'z, x, y'
47 'y, z, x'
48 'x, y, z'
loop_
_atom_type_symbol
_atom_type_oxidation_number
Cs1+ 1
Ge2+ 2
Cl1- -1
loop_
_atom_site_label
_atom_site_type_symbol
_atom_site_symmetry_multiplicity
_atom_site_Wyckoff_symbol
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_B_iso_or_equiv
_atom_site_occupancy
Cs1 Cs1+ 1 a 0 0 0 7.46 1.
Ge1 Ge2+ 1 b 0.5 0.5 0.5 0.85 1.
Cl1 Cl1- 6 f 0.5 0.0686 0.5 3.56 0.5
#End of TTdata_23122-ICSD
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$\begingroup$ Thank you very much Sir for your reply. If I replace Br atom with Cl atom in the scf.in file and then perform vc-relax, will this procedure be okay? $\endgroup$ Jul 26 at 3:11
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$\begingroup$ but I could not get it because I requested a username and password, and this service is available for UK universities only. Can you help me please $\endgroup$ Jul 26 at 5:41
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$\begingroup$ I added the CIF for the CsGeCl3 in my answer. You can use it as it. About interchanging the atoms, I need to know how the material is formed, if the positions will be equivalents, etc. I cannot answer right now without studying the material. And yes, that database is a pay service (as many others). $\endgroup$– Camps ♦Jul 26 at 12:17