Alignment of 3D-structures by the method of 2D-projections

The three-dimensional shape of a molecule can be analyzed by considering a series of two-dimensional projections. By comparing projections of two mole cules a mechanism for the alignment of three-dimensional structures is deri ved. The efficiency of this two-dimensional comparison permits a sequential search over alignment space thereby eliminating misconvergence problems th at plague many existing automated alignment procedures. Examples of molecul ar alignment by this method are illustrated together with several variation s on the basic procedure. These variations permit a wide variety of structu res to be considered. The existence of a reliable and efficient automated a lignment methodology has important ramifications fur QSAR studies and gener al chemical informatics.