LIKELIHOOD-BASED MODIFICATION OF EXPERIMENTAL CRYSTAL STRUCTURE ELECTRON DENSITY MAPS

A maximum-likelihood method for improves an electron density map of an experimental crystal structure. A likelihood of a set of structure factors {Fh} is formed for the experimental crystal structure as (1) the likelihood of having obtained an observed set of structure factors {FhOBS} if structure factor set {Fh} was correct, and (2) the likelihood that an electron density map resulting from {Fh} is consistent with selected prior knowledge about the experimental crystal structure. The set of structure factors {Fh} is then adjusted to maximize the likelihood of {Fh} for the experimental crystal structure. An improved electron density map is constructed with the maximized structure factors.