W0198

A Continuous Diffraction Intensity Function and its Implications for Phase Determination. Abelardo M. Silva^* and Jorge Navaza², ¹National Cancer Institute/SAIC, Frederick, Maryland 21702, USA, ²Faculte de Pharmacie, 92290 Chatenay-Malabry, France

It has been argued that the knowledge of a continuous diffraction intensity function would help solving the phase problem. However, to construct such a function by direct application of Shannon's interpolation equation is not feasible because it requires intensity values at half Miller indices, which are not experimentally accessible. We demonstrate that the continuous function can be determined using intensities measured from independent but related crystals, having different unit cell parameters. We show how phase information can be recovered from the continuos function, discuss a related Hilbert transform algorithm, and propose using NON-isomorphous heavy-atom derivatives for phase determination.