title: The phase problem in neutron crystallography.
abstract: The straightforward solution of the crystal structure of cyclosporin (C(62)H(111)N(11)O(12).H(2)O) by a modified Shake-and-Bake procedure, using experimental neutron diffraction data alone, shows that the positivity of the density function is not a necessary prerequisite for solving the phase problem. The initial applications suggest the intriguing possibility that positivity may actually be a hindrance.
authors.affiliation: Hauptman-Woodward Medical Research Institute, Inc., 73 High Street, Buffalo, NY 14203-1196, USA. hauptman@hwi.buffalo.edu
authors.forename: Herbert A
authors.initials: HA
authors.lastname: Hauptman
authors.forename: David A
authors.initials: DA
authors.lastname: Langs
mesh_terms: D000465:Algorithms; D016572:Cyclosporine / Q000737:chemistry; D008958:Models, Molecular; D015233:Models, Statistical; D033363:Neutron Diffraction / Q000379:methods*; D012680:Sensitivity and Specificity
chemical_list: D016572:Cyclosporine