Acta Phys. -Chim. Sin. ›› 1991, Vol. 7 ›› Issue (04): 449-455.doi: 10.3866/PKU.WHXB19910414

• ARTICLE • Previous Articles     Next Articles

Studies of Trial and Error Methof for Crystal Structural Determinations(II)——Modifications of the Super-Solution Phase Eqation

Hou Yong-Geng; Ma Zhi-Mei; Fu Heng   

  1. Institute of Chemistry, Academia Sinica, Beijing 100080
  • Received:1990-01-18 Revised:1990-12-10 Published:1991-08-15
  • Contact: Hou Yong-Geng

Abstract: In this paper, it is demonstrated that |E(k)E(h-k)| is a structure invari ant. On the basis of this knowledge, three models, which can be used to estimate the value of |E(k)E(h-k)| from normalized structure amplitudes |E|, are proposed. In particular, |E(k)E(h-k)|_(QE), which is deduced from the second neighborhood principle of quartet structure invariants, is an ideal estimation of |E(k)E(h-k)| with known phase lacks. It is expected that |E(k)E(h-k)|_(QE) will improve the function of super-solution phase equation in systematical trial and error method and increase the accuracy of the phase values to be determined.

Key words: Phase equation, Structure invariant, Direct method