Abstract

<h2>Acta Crystallographica Section B</h2><h3>Structural Crystallography and Crystal Chemistry</h3><h3>0567-7408</h3> <h2>research papers</h2> Volume 38 Part 4 Pages 1065-1070 April 1982 <h2>The structure of silver fluoride iodide hydrate Ag 7 I 2 F 5 .2.5H 2 O</h2> K. Persson and B. Holmberg Acta Cryst. (1982). B38, 1065-1070 The Structure of Silver Fluoride Iodide Hydrate AgTI2F5. 2.5H20 BY KENNETH PERSSON AND BERTIL HOLMBERG Physical Chemistry 1, Chemical Center, University of Lund, POB 740, S-220 07 Lund 7, Sweden (Received 30 June 1981 ; accepted 5 October 198 l) Abstract Ag712Fs.2.5H20 is monoclinic, space group P2~/n, with a = 7.4061(6), b = 17.8298(32), c = 9.3618 (9) A, fl = 91.278 (8)°, Z = 4, and Dm = 5.9, Dx = 6.17 Mg m-3. The structure was determined from single-crystal X-ray diffractometer data. The refine- ment based on 2961 reflexions and anisotropic thermal parameters converged to a final R value of 0-039. Layers built up by Ag, I and F atoms are joined by a hydrogen-bond system containing four-membered (H20. • • F)2 rings. The I atoms are rather unsymmetri- cally surrounded by seven or eight Ag atoms. Five of these describe a pentagon. These pentagons share edges to form layers, two per