title: The direct determination of phase invariants provided by diffraction data measured at two different temperatures.
abstract: A procedure is described for the determination of the crystal structure phase invariants of a compound based on diffraction data measured at two different temperatures. This temperature difference replacement (TDR) technique is shown to provide phase-invariant information from experimentally measured X-ray diffraction data for two different test structures. Although the new method does not appear to be as powerful as single-derivative isomorphous replacement (SIR) phasing, it does appear to be capable of reliably determining a limited number of negative as well as positive phase-restricted invariants for structures containing as many as 300 non-H atoms in the asymmetric unit.
authors.affiliation: Medical Foundation of Buffalo, Inc., NY 14203.
authors.forename: D A
authors.initials: DA
authors.lastname: Langs
mesh_terms: D000595:Amino Acid Sequence; D006096:Gramicidin / Q000737:chemistry; D008969:Molecular Sequence Data; D015394:Molecular Structure; D010455:Peptides / Q000737:chemistry; D013696:Temperature; D014961:X-Ray Diffraction / Q000379:methods*
chemical_list: D010455:Peptides; D006096:Gramicidin