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Standard deviations of lattice parameters obtained from powder data measurements
Author(s) -
Warczewski J.,
De Wolff P. M.
Publication year - 1974
Publication title -
journal of applied crystallography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.429
H-Index - 162
ISSN - 1600-5767
DOI - 10.1107/s0021889874010478
Subject(s) - lattice (music) , standard deviation , powder diffraction , diffraction , line (geometry) , systematic error , standard error , algorithm , computational physics , mathematics , computer science , chemistry , statistics , crystallography , optics , physics , geometry , acoustics
A method is described for least‐squares refinement of lattice parameters from powder diffraction measurements. Unusual features are: (1) an individual standard error can be assigned to each line, (2) variances and covariances for all parameters are calculated from those errors, (3) the three parameters of a second‐degree correction curve are added to the unknowns, and (4) the method uses both the measurements of internal standard lines – if any – and the lines of the substance under investigation for the simultaneous refinement of all unknowns. Because of the last‐mentioned feature, the method is especially suitable for measurements obtained from Guinier cameras. The description of a computer program based on this method is added.