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A Computer Program for Determining Accurate Parameters from Powder Data

Published online by Cambridge University Press:  06 March 2019

Rodney P. Elliott*
Affiliation:
IIT Research Institute Chicago Illinois
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Abstract

An IBM 7090 computer program has been written to determine precise lattice parameters for cubic, tetragonal, orthorhombic, and hexagonal systems. Leastsquares analysis is made with data fitted to the equation

where E is the eccentricity and A. is the absorption-divergence error. The computer program will make the least-squares analysis with neither, either, or both of the error(s) included. Data can then be reprocessed for other combinations of errors. After having determined the lattice parameter(s), on request, the computer program will predict the interplanar spacings, including the errors, so that observed data in the high-angle region may be indexed by comparison. Use of the program indicates that the most consistently reproducible parameters are obtained using only A, the absorption—divergence error.

Type
Research Article
Copyright
Copyright © International Centre for Diffraction Data 1964

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References

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