The static deformation density of tetrafluoroterephthalonitrile (TFT) from the Zurich X-ray data at 98 K
Abstract
<h2>Acta Crystallographica Section B</h2><h3>Structural Science</h3><h3>0108-7681</h3> <h2>research papers</h2> Volume 40 Part 5 Pages 484-492 October 1984 <h2>The static deformation density of tetrafluoroterephthalonitrile (TFT) from the Zürich X-ray data at 98 K</h2> F. L. Hirshfeld 484 Acta Cryst. (1984). B40, 484 a.92 The Static Deformation Density of Tetrafluoroterephthalonitrile (TFF) from the Ziirich X-ray Data at 98 K BY F. L. HIRSHFELD Department of Structural Chemistry, The Weizmann Institute of Science, Rehovot 76100, Israel (Received 1 March 1984; accepted 11 May 1984) Dedicated to Professor Jack D. Dunitz on the occasion of his 60th birthday Abstract The low-temperature X-ray data for TFT measured by Dunitz and coworkers have led, via multipole refinement, to a static deformation density map. In support of the data and the model, final discrepancy indices are R = 0.036, Rw(F2) = 0-019, GOF= 1.140, the discrepancies AF show negligible systematic trends and yield a residual density showing mainly random noise, vibration parameters satisfy the rigid- bond test, and the total electron density is everywhere positive. Results accord well with the high-order refinement of Dunitz et al. The deformation density closely resembles experimental and theoretical maps of related molecules. Both -n--conjugative and or- inductive effects seem responsible for