W0228

Successful Use of Synchrotron Radiation for Structure Solution Using a Very Small (2.5 x 2.5 x 8 (m³) Crystal of KZnPO₄. R.W.Broach^a, R.L.Bedard^a, J.J.Pluth^b, A.Bram^c, C.Riekel^c, H.-P.Weber^c; ^aUOP LLC, 50 E. Algonquin Rd., Des Plaines, Illinois 60017; ^bDepartment of Geophysical Sciences, 5734 South Ellis Avenue, University of Chicago, Chicago, Illinois 60637; ^cEuropean Synchrotron Radiation Facility, BP 220, 38043, Genoble, France

Figure 1. C-axis projection (polyhedral representation) of the KZnPO₄ framework.

New techniques for handling crystals and collecting data allow structure solution from micrometer sized crystals. Our experience using these techniques for determining the crystal structure of a new KZnPO₄ microporous material are described. Crystals were manipulated and mounted using a micromanipulator attached to a Nikon optical microscope. Data on a 2.5 x 2.5 x 8 (m³ single crystal were collected at Beamline Insertion Device 13 at the European Synchrotron Radiation Facility. Lattice constants of the orthorhombic cell in space group Ccc2 are a = 13.812(3), b = 13.836(3), and c = 13.134(3) Å. The structure refined to a final R = 0.092 using all 1866 reflections. The structure is disordered and was modeled by adding a second component to the single crystal refinement. Electron diffraction spots reveal streaking along the [100] direction consistent with the disordered model. The structure of KZnPO₄ is similar to the zeolite mineral edingtonite (EDI). It consists of a four-connected three-dimensional framework of Zn and P tetrahedra producing a three-dimensional eight-ring channel system. The channels are nearly circular along the a- and b-axis directions, but are elliptical along c as shown in Figure 1. Potassium atoms (not shown in the figure) occupy sites in the channels.