[Wien] ROTDEF-error

[Stefaan Cottenier]

First shot: after cif2struct, change the 0.6667 that is due to this line

Si1 Si4+ 3 a 0.472(2) 0 0.6667 0.7(3) 1. 0

into 0.6666667  (7 times 6, one times 7). Then run sgroup, and use 
case.struct_sgroup as your final case.struct.

It might be that sgroup does not recognize the proper symmetry if 
instead of 2/3 you give 0.6667.

Stefaan



Daniel Meljanac wrote:
> Dear Users,
> 
> I am getting ROTDEF - Error after running DSTART. In the Userguide it 
> says that
> "This indicates that in your case.struct file either the positions of 
> equivalent atoms are not specified correctly (only positive coordinates 
> allowed!!) or the symmetry operations are wrong." But I used the input 
> data from a .cif file, which I am attaching.
> 
> I don't know  how to fix the problem. Could it be that something is 
> wrong in the .cif file, or I am doing something wrong?
> 
> Could anybody help me please?Thanks in advance.
> 
> Best regards,
> Daniel Meljanac
> 
> #(C) 2010 by Fachinformationszentrum Karlsruhe. All rights reserved.
> data_16331-ICSD
> _database_code_ICSD 16331
> _audit_creation_date 1980-01-01
> _audit_update_record 2006-04-01
> _chemical_name_systematic 'Silicon oxide - alpha'
> _chemical_formula_structural 'Si O2'
> _chemical_formula_sum 'O2 Si1'
> _chemical_name_structure_type Quartz,low
> _chemical_name_mineral 'Quartz low'
> _exptl_crystal_density_diffrn 2.64
> _cell_measurement_temperature 293.
> #Default value included by FIZ Karlsruhe
> _cell_measurement_pressure 101.325
> #Default value included by FIZ Karlsruhe
> _publ_section_title 'Structure determination of alpha-quartz up to 
> 68*10exp8 Pa'
> loop_
> _citation_id
> _citation_journal_full
> _citation_year
> _citation_journal_volume
> _citation_page_first
> _citation_page_last
> _citation_journal_id_ASTM
> primary 'Acta Crystallographica B (24,1968-38,1982)' 1979 35 550 555 ACBCAR
> loop_
> _publ_author_name
> 'd'Amour, H.'
> 'Denner, W.'
> 'Schulz, H.'
> _cell_length_a 4.921(1)
> _cell_length_b 4.921(1)
> _cell_length_c 5.400(4)
> _cell_angle_alpha 90.
> _cell_angle_beta 90.
> _cell_angle_gamma 120.
> _cell_volume 113.25
> _cell_formula_units_Z 3
> _symmetry_space_group_name_H-M 'P 32 2 1'
> _symmetry_Int_Tables_number 154
> loop_
> _symmetry_equiv_pos_site_id
> _symmetry_equiv_pos_as_xyz
> 1 '-x, -x+y, -z+2/3'
> 2 'x-y, -y, -z+1/3'
> 3 'y, x, -z'
> 4 '-x+y, -x, z+1/3'
> 5 '-y, x-y, z+2/3'
> 6 'x, y, z'
> loop_
> _atom_type_symbol
> _atom_type_oxidation_number
> Si4+ 4
> O2- -2
> 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
> _atom_site_attached_hydrogens
> Si1 Si4+ 3 a 0.472(2) 0 0.6667 0.7(3) 1. 0
> O1 O2- 6 c 0.408(4) 0.265(4) 0.786(2) 1.0(5) 1. 0
> #End of data_16331-ICSD
> 
> 
> ------------------------------------------------------------------------
> 
> _______________________________________________
> Wien mailing list
> Wien at zeus.theochem.tuwien.ac.at
> http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien


-- 
Stefaan Cottenier
Center for Molecular Modeling (CMM)
Ghent University
Technologiepark 903 (2nd floor)
BE-9052 Zwijnaarde
Belgium

http://molmod.Ugent.be
email: Stefaan . Cottenier /at/ UGent . be