A multisolution procedureviatendentially maximally entropical starting sets

Abstract

Large starting sets of random phases are in general inconsistent with positivity and atomicity of the electron density. A correct solution can be achieved from them because the tangent formula is a process which maximizes entropy under physical constraints involving the positivity and atomicity of electron density. Starting sets which are themselves tendentially maximally entropical can be created by associating phase shifts A, generated according to the yon Mises distribution of each triplet phase, to some (from 50 to 300) triplet invariants. Then the phases generated via these perturbed triplets are samples of the phase population expected to be maximally entropical on 0108-7673/87/060797-06501.50 the basis of the prior information. Experimental tests show that the method may be a useful alternative to other conventional multisolution methods.

A reconsideration of the role of two-phase seminvariants. V. Basic results

“…Only four structures remain unsolved by SIR [however, it cannot be concluded that SIR is unable to solve those structures using non-default conditions; see for example, Burla, Giacovazzo & Polidori (1987)]. Very often the ratio (number of correct solutions/number of trials) is larger in PROT 2 than in PROT 1.…”