E335: Analysis Of An Extensive Imaging-Plate Data Set On Cr(Nh3)6Cr(Cn)6, Collected With 0.394 Synchrotron Radiation

E335

Analysis of an Extensive Imaging-Plate Data Set on Cr(NH₃)₆Cr(CN)₆, Collected With 0.394 Å Synchrotron Radiation. J. Zaleski, R. Bolotovsky and P. Coppens, Chemistry Department, State University of New York at Buffalo, Buffalo, NY 14260-3000

Area detectors have the potential to greatly speed up charge density analysis, but their accuracy must be analyzed in detail before this goal can be achieved. Even when good R-merge factors are obtained, an intensity dependent bias may exist, which can be due to the recording process, the integration method and/or the sorting procedure. We present an analysis of a 30 K data set on hexaminechromium hexacyanochromate Cr(NH₃)₆Cr(CN)₆, containing reflections up to sin[theta]/[lambda] = 2Å^-1, collected at the SUNY X3A1 station at NSLS [1].

In order to assess uncertainties introduced by the integration procedure, reflections have been integrated by a profile fitting method using Denzo [2], as well as by the seed-skewness program Hippo [3]. An analysis of the intensity ratios as a function of intensity and sin[theta]/[lambda] will be presented. Both structure factor sets have been used as input for a multipole refinement using the XD package [4].

Refinement results are compared with each other, with theoretical calculations [5] and with values derived in earlier studies [6].

References:

[1] R. Bolotovsky, Thesis, State University of New York at Buffalo, April 1996. [2] Z. Otwinowski and W. Minor, Computer Program DENZO. [3] R. Bolotovsky, M. A. White, A. Darovsky and P. Coppens, J. Appl. Cryst. 28, 86-95 (1995); R. Bolotovsky and P. Coppens, J. Appl. Cryst. (1997), In Press. [4] T. Koritsansky et al., XD: A program for refinement and analysis of charge density. [5] Sano, M., Kashiwagi, H. & Yamatera, H. (1982). Inorg. Chem. 21, 3837-3841. [6] R. Bolotovsky, A. Darovsky, V. Kezerashvili and P. Coppens, J. Synch. Rad. 2, 181-184 (1995).

Support of this work by the National Science Foundation (CHE9317770 and CHE9615586) is gratefully acknowledged. The SUNY X3 beamline at NSLS is supported by the Division of Basic Energy Sciences of the U.S. Department of Energy (DE-FG02-86ER45231).