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331. PPUR: Powder Pattern Program
by Joel S. Miller and Stephen Z. Goldberg, Xerox Corporation, Rochester, New York 14644 This interactive FORTRAN IV program has been written to aid in the characterization of crystalline materials by calculating and plotting the theoretical positions of the Bragg reflections as a function of 20. The program is capable of calculating and plotting Bragg reflections for any crystalline substance and is intended to aid in the comparison of isomorphous materials as well as in the characterization of new substances. Provisions have been made to account for systematic absences associated with any space group. The data necessary for the calculation of any powder pattern included the real or reciprocal cell constants, parameters associated with the extent of calculation desired, and, optionally, the abbreviation of the crystal system. Powder pattern plots with arbitrary intensities may be specified for direct comparison with either diffractometer traces or Debye-Scherrer film data. The abscissa of the powder pattern plot may be specified to be the same scale as the observed data to facilitate comparison by superposition. Likewise, a provision to generate circular Debye-Scherrer powder patterns is available for facile comparison with film data. Furthermore, a choice of either a high resolution (use of KO(a,1) and KO(a,2)) or low resolution (use of Ka) calculation based on the Ka radiations of Mo, Fe, Cr, Co, or Cu may be utilized. The data obtained from the program may be used to evaluate quickly the powder patterns of any crystalline substance. FORTRAN IV (IBM H LEVEL COMPILER) Lines of Code: 584 Recommended Citation: J. S. Miller and S. Z. Goldberg, QCPE 11, 331 (1977). |