ISSN:
1600-5724
Source:
Crystallography Journals Online : IUCR Backfile Archive 1948-2001
Topics:
Chemistry and Pharmacology
,
Geosciences
,
Physics
Notes:
A procedure is given for estimating the variance ratio σ21/σ211, of two models of a crystal structure where σ21 and σ211 are the variances of the weighted (|Fo| - |Fc|) distributions for models I and II, respectively, and |Fo| and |Fc| are the observed and calculated structure factors. The procedure provides a statistical test of the hypothesis that the above ratio is unity for a given pair of models and, thus, whether one of the models offers a significantly better description of the crystal structure. The method is applicable to crystallographic problems in which each of two or more structural models is expressed in terms of the same set of parameters. It has been applied to a number of atom-assignment problems, and the results are compared with those from Hamilton's R-factor ratio test.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1107/S0567739478001989
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