Published online by Cambridge University Press: 06 March 2019
Techniques for the computer-assisted evaluation of crystallographic data have been developed to improve the data compilations of the NBS Crystal Data Center and the JCPDS—International Centre for Diffraction Data. The resulting computer program, NBS*ATDS80, can be used for the analysis of unit-cell and powder data by the general scientific community as well. NBS*AIDS80 is written in FORTRAN to permit implementation on a wide variety of computers, and input may be from cards or from a terminal. The research and analysis components that will be of use to the individual scientist include the following:
1) Calculation of the Crystal Data cell, determinative ratios, and space group for the comparison and reporting of unit cell parameters in a standard setting and for the identification of unknowns.
2) Determination of the reduced cell, reduced form number, and the unit cell with the highest metric symmetry.
3) Calculation of the molecular weight from the formula using the most recent atomic weights, and comparison of the density calculated by the program with the measured density.
4) Generation of d-spacings and indices for any input cell and crystal system.
5) Comparison of input powder data with calculated d-spacings, indexing of lines based on known unit cell parameters, and calculation of figures of merit.