ReX.Cell: a user-friendly program for powder diffraction indexing

2012 ◽  
Vol 46 (1) ◽  
pp. 259-261 ◽  
Author(s):  
Mauro Bortolotti ◽  
Ivan Lonardelli
Keyword(s):  
Powder Diffraction ◽  
Diffraction Data ◽  
Powder Diffraction Data ◽  
Data Smoothing ◽  
Data Indexing ◽  
Java Programming ◽  
Interactive Interface ◽  
Peak Finding ◽  
Data Formats ◽  
User Friendly

ReX.Cellis a novel software package dedicated to the automation of crystal cell indexing starting from powder diffraction data. The program aims to help both novice and experienced powder diffractionists overcome the practical difficulties encountered during powder data indexing, by offering a user-friendly highly interactive interface to classical indexing engines. The software provides a wizard-style approach, accompanying the user through all the typical steps of the indexing procedure: preliminary data processing, background subtraction, data smoothing, peak finding and finally autoindexing. Each step can be carried out automatically or fine-tuned through custom options; in either mode, algorithms and filters are applied in real time to the diffraction data, giving an immediate visual feedback. The program is written in the Java programming language and runs on several different operating systems; source code is provided to allow developers to add support for additional indexing programs and/or powder diffraction data formats.

QUALX2.0: a qualitative phase analysis software using the freely available database POW_COD

2015 ◽  
Vol 48 (2) ◽  
pp. 598-603 ◽  
Author(s):  
Angela Altomare ◽  
Nicola Corriero ◽  
Corrado Cuocci ◽  
Aurelia Falcicchio ◽  
Anna Moliterni ◽  
...  
Keyword(s):  
Phase Analysis ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Phase Identification ◽  
Powder Diffraction Data ◽  
Structure Information ◽  
Previous Version ◽  
Experimental Diffraction Pattern ◽  
User Friendly ◽  
Qualitative Phase

QUALX2.0is the new version ofQUALX, a computer program for qualitative phase analysis by powder diffraction data. The previous version ofQUALXwas able to carry out phase identification by querying the PDF-2 commercial database. The main novelty ofQUALX2.0is the possibility of querying also a freely available database, POW_COD. POW_COD has been built up by starting from the structure information contained in the Crystallography Open Database (COD). The latter is a growing collection of diffraction data, freely downloadable from the web, corresponding to inorganic, metal–organic, organic and mineral structures.QUALX2.0retains the main capabilities of the previous version: (a) automatically estimating and subtracting the background; (b) locating the experimental diffraction peaks; (c) searching the database for single-phase pattern(s) best matching to the experimental powder diffraction data; (d) taking into account suitable restraints in the search; (e) performing a semi-quantitative analysis; (f) enabling the change of default choices and strategiesviaa user-friendly graphic interface. The advances ofQUALX2.0with respect toQUALXinclude (i) a wider variety of types of importable ASCII file containing the experimental diffraction pattern and (ii) new search–match options. The program, written in Fortran and C++, runs on PCs under the Windows operating system. The POW_COD database is exported in SQLite3 format.

QPDA – A User-Friendly, Interactive Program for Quantitative Phase and Crystal Size/Strain Analysis of Powder Diffraction Data

1990 ◽  
Vol 5 (4) ◽  
pp. 195-199 ◽  
Author(s):  
I.C. Madsen ◽  
R.J. Hill
Keyword(s):  
Powder Diffraction ◽  
Diffraction Data ◽  
Crystal Size ◽  
Rietveld Method ◽  
Structure Refinement ◽  
Inorganic Materials ◽  
Powder Diffraction Data ◽  
Wide Range ◽  
Structural Applications ◽  
User Friendly

AbstractRecent developments in the Rietveld method for the analysis of powder diffraction data have seen the method evolve from its original purpose of crystal structure refinement to include the determination of phase abundance in polycrystalline mixtures and the estimation of crystal size and strain parameters. However, the Rietveld method is not easy to use and may deter many powder diffractionists, who are not interested in structure refinement per se, from using the method in its non-structural applications.In order to overcome the difficulties in using the Rietveld method, a program, QPDA (for Quantitative Powder Diffraction Analysis), has been written that sets the conditions necessary for a single or multi-phase refinement, runs the Rietveld program and extracts phase abundance and size/strain information from the refined parameters. The program comprises a user-friendly, default-driven system of subroutines, written initially in VAX Fortran, and operates from a database of inorganic materials frequently encountered in a wide range of minerals and materials science industries.

Renewed interest in powder diffraction data indexing

2004 ◽  
Vol 219 (12) ◽  
Author(s):  
Jörg Bergmann ◽  
Armel Le Bail ◽  
Robin Shirley ◽  
Victor Zlokazov
Keyword(s):  
Data Quality ◽  
User Experience ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Powder Diffraction Data ◽  
High Quality ◽  
Data Indexing ◽  
High Data ◽  
Difficult Situations ◽  
Bethanechol Chloride

AbstractRecently released powder indexing programs are reviewed and placed in competition with the established programs (ITO, TREOR, DICVOL, etc.) through a series of problems selected among previously unindexed ICDD entries designated as “high quality”. Benchmarks are provided for testing indexing programs, based on the bethanechol chloride powder diffraction data. Applying these benchmarks leads to a classification (with respect to this specific example) of indexing programs as they face progressively more difficult situations. High data quality and the user experience to obtain it are concluded to remain the best way to indexing success, given that nearly all programs produce excellent results with excellent data. Lack of attention to data quality, even if followed by use of the most efficient programs, will usually lead to failure. It is demonstrated how not restricting oneself to a single indexing program can considerably increase the chances of success.

scholarly journals QPDA – A User-Friendly, Interactive Program for Quantitative Phase and Crystal Size/Strain Analysis of Powder Diffraction Data

1991 ◽  
Vol 6 (1) ◽  
pp. 52-52
Author(s):  
I.C. Madsen ◽  
R.J. Hill
Keyword(s):  
Powder Diffraction ◽  
Diffraction Data ◽  
Crystal Size ◽  
Rietveld Method ◽  
Structure Refinement ◽  
Inorganic Materials ◽  
Powder Diffraction Data ◽  
Wide Range ◽  
Structural Applications ◽  
User Friendly

AbstractRecent developments in the Rietveld method for the analysis of powder diffraction data have seen the method evolve from its original purpose of crystal structure refinement to nclude the determination of phase abundance in polycrysalline mixtures and the estimation of crystal size and strain parameters. However, the Rietveld method is not easy to use and may deter many powder diffractionists, who are not inerested in structure refinement per se, from using the method in its non-structural applications.In order to overcome the difficulties in using the Rietveld method, a program, QPDA (for Quantitative Powder Diffraction Analysis), has been written that sets the conditions necessary for a single or multi-phase refinement, runs the Rietveld program and extracts phase abundance and size/strain information from the refined parameters. The program comprises a user-friendly, default-driven system of subroutines, written initially in VAX Fortran, and operates from a database of inorganic materials frequently encountered in a wide range of minerals and materials science industries.Equations (3) and (5) should be corrected to read as follows:

DASH: a program for crystal structure determination from powder diffraction data

2006 ◽  
Vol 39 (6) ◽  
pp. 910-915 ◽  
Author(s):  
William I. F. David ◽  
Kenneth Shankland ◽  
Jacco van de Streek ◽  
Elna Pidcock ◽  
W. D. Samuel Motherwell ◽  
...  
Keyword(s):  
Simulated Annealing ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Global Minimum ◽  
Molecular Structures ◽  
Powder Diffraction Data ◽  
Peak Fitting ◽  
Structure Factors ◽  
Integrated Intensities ◽  
User Friendly

DASHis a user-friendly graphical-user-interface-driven computer program for solving crystal structures from X-ray powder diffraction data, optimized for molecular structures. Algorithms for multiple peak fitting, unit-cell indexing and space-group determination are included as part of the program. Molecular models can be read in a number of formats and automatically converted to Z-matrices in which flexible torsion angles are automatically identified. Simulated annealing is used to search for the global minimum in the space that describes the agreement between observed and calculated structure factors. The simulated annealing process is very fast, which in part is due to the use of correlated integrated intensities rather than the full powder pattern. Automatic minimization of the structures obtained by simulated annealing and automatic overlay of solutions assist in assessing the reproducibility of the best solution, and therefore in determining the likelihood that the global minimum has been obtained.

FIDDLE. Simultaneous Indexing and Structure Solution from Powder Diffraction Data using a Genetic Algorithm and Correlation Functions

2019 ◽  
Author(s):  
Carmen Guguta ◽  
Jan M.M. Smits ◽  
Rene de Gelder
Keyword(s):  
Genetic Algorithm ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Correlation Functions ◽  
Cross Correlation ◽  
Simultaneous Optimization ◽  
Powder Diffraction Data ◽  
Structure Solution ◽  
Matching Technique

A method for the determination of crystal structures from powder diffraction data is presented that circumvents the difficulties associated with separate indexing. For the simultaneous optimization of the parameters that describe a crystal structure a genetic algorithm is used together with a pattern matching technique based on auto and cross correlation functions.<br>

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