A new vector-search rotation function: image-seeking functions revisited in macromolecular crystallography

A new rotation function in Patterson space is described. An image-seeking f unction can be defined as a criterion of rt between the observed Patterson map and a suitable vector set extracted from a specially calculated Patters on map of the search model. The behaviour of image-seeking functions has ap peared to be heavily dependent on certain relations between some statistica l parameters of both maps. A new algorithm, which carries out the crucial s tep of selecting the appropriate vector set from the search model, has been established. As a consequence of the combination of these two preceding re sults, a new vector-search rotation function has been proposed and tested.