On the application of phase relationships to complex structures. XVIII.RANTAN–randomMULTAN

To overcome the disadvantages of a small starting set in MULTAN a technique is described whereby a large number of phases are given random values with low weights and then refined by a weighted tangent formula. The effectiveness of the process depends quite critically on assigning suitable weights to phase estimates and on a fairly tight control of the refinement. Examples of the application of the method are given for a number of structures, many of which are difficult to solve by direct methods.