Titlebook: Direct Methods of Solving Crystal Structures; Henk Schenk Book 1991 Springer Science+Business Media New York 1991 DSI_D012

无能的人

perpetual

Starting Set Determinaton,For most practical applications of direct methods it is convenient to distinguish the following stages:.In this chapter we discuss some practical aspects of (a) and (b) with emphasis on the determination of the starting set. But how to choose starting reflections depends on what we plan to do with them!

OVER

Tangent Formula, Tangent Refinement and Multisolution Methods,A single three-phase relationship, cast in the form . is capable of giving an estimate of the value of ϕ(h) if the values of the phases on the right-hand side are known. The question now arises of finding the overall estimate if there are several pairs of known phases, the estimate from each of which might well be different.

Adherent

obviate

Introduction to Maximum Entropy,The Maximum Entropy Method (MEM) is not a completely different approach from Conventional Direct Methods (CDM) : it is an . of the latter at the level of the techniques of Analytic Probability Theory on which they are based.

resuscitation

狂热语言

The Calculation of Normalized Structure Factors and of Triplet Invariants, do not give rise to systematic absences. It also allows to obtain an estimate both of the scale factor by which one has to multiply the measured data to scale them to their absolute value, and of the temperature factor. Finally it is a basic step in the calculation of ., which will be seen to be useful quantities when using direct methods.

Antigen

The Joint Probability Distribution of Three Structure Factors Leading to a Distribution for the Triof three structure factors via its characteristic function. Assuming an a priori probabilistic model of uniformly and independently distributed atoms, the calculations result in the well-known Cochran distribution for the triplet phase sum.

evasive

不给啤

Mayank Jyotsna Soni,Soumya Sarkared straightforward from I. but the relative phases . are lost in the experiment and cause the so called phase problem. Direct methods try to evaluate phases . “directly” from the measured diffraction intensities I. by using relationships among the phases, relationships, whose values are based on the