CIF2Cell: Generating geometries for electronic structure programs

The CIF2Cell program generates the geometrical setup for a number of electronic structure programs based on the crystallographic information in a Crystallographic Information Framework (CIF) file. The program will retrieve the space group number, Wyckoff positions and crystallographic parameters, make a sensible choice for Bravais lattice vectors (primitive or principal cell) and generate all atomic positions. Supercells can be generated and alloys are handled gracefully. The code currently has output interfaces to the electronic structure programs ABINIT, CASTEP, CPMD, Crystal, Elk, Exciting, EMTO, Fleur, RSPt, Siesta and VASP.

Program summary

Program title: CIF2CellCatalogue identifier: AEIM_v1_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEIM_v1_0.htmlProgram obtainable from: CPC Program Library, Queen's University, Belfast, N. IrelandLicensing provisions: GNU GPL version 3No. of lines in distributed program, including test data, etc.: 12 691No. of bytes in distributed program, including test data, etc.: 74 933Distribution format: tar.gzProgramming language: Python (versions 2.4–2.7)Computer: Any computer that can run Python (versions 2.4–2.7)Operating system: Any operating system that can run Python (versions 2.4–2.7)Classification: 7.3, 7.8, 8External routines: PyCIFRW [1]Nature of problem: Generate the geometrical setup of a crystallographic cell for a variety of electronic structure programs from data contained in a CIF file.Solution method: The CIF file is parsed using routines contained in the library PyCIFRW [1], and crystallographic as well as bibliographic information is extracted. The program then generates the principal cell from symmetry information, crystal parameters, space group number and Wyckoff sites. Reduction to a primitive cell is then performed, and the resulting cell is output to suitably named files along with documentation of the information source generated from any bibliographic information contained in the CIF file. If the space group symmetries is not present in the CIF file the program will fall back on internal tables, so only the minimal input of space group, crystal parameters and Wyckoff positions are required. Additional key features are handling of alloys and supercell generation.Additional comments: Currently implements support for the following general purpose electronic structure programs: ABINIT [2,3], CASTEP [4], CPMD [5], Crystal [6], Elk [7], exciting [8], EMTO [9], Fleur [10], RSPt [11], Siesta [12] and VASP [13–16].Running time: The examples provided in the distribution take only seconds to run.References:

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  S.J. Clark, M.D. Segall, C.J. Pickard, P.J. Hasnip, M.J. Probert, K. Refson, M.C. Payne, First principles methods using CASTEP, Zeitschrift für Kristallographie 220 (12) (2005) 567–570.

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  URL http://www.cpmd.org.

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  URL http://elk.sourceforge.net.

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  URL http://exciting-code.org.

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  L. Vitos, Computational Quantum Mechanics for Materials Engineers; The EMTO Method and Applications, Springer, London, 2007, doi:10.1007/978-1-84628-951-4.

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  URL http://www.flapw.de.

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  G. Kresse, J. Furthmüller, Efficient iterative schemes for ab initio total-energy calculations using a plane-wave basis set, Phys. Rev. B 54 (16) (1996) 11169–11186, doi:10.1103/PhysRevB.54.11169.

     

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