Date of Award
Doctor of Philosophy
Patterson manipulation methods and direct methods, such and those employing the well-known (SIGMA)(,2) relation, are often viewed as being distinctly different approaches to structure determination. In the first part of this thesis a method which combines the two approaches while retaining the advantages of both was developed;The basic assumption used in our method is that (rho)('2) (TURN) M(,ps) (.) (rho), where (rho) and M(,ps) are the electron density and Patterson superposi- tion functions, respectively. This results in a (SIGMA)(,2)-like relation in reciprocal space in which one of the E's in the product is replaced by G, a structure factor-like quantity obtained from a Fourier trans- form of the Patterson superposition function;This new relation has been proven to be effective in both centric and acentric cases. The details of the theory and its application to both model and real structures are presented;The construction and development of an in-lab EXAFS facility using a rotating anode X-ray source are presented in the second part of this thesis. These include spectrometer alignment, automa- tion, tests of the electronic detector systems, improvement of the;energy resolution and developments of both data acquisition and data reduction programs; ('1)DOE Report IS-T-1221. This work was performed under contract No. W-7405-Eng-82 with the U.S. Department of Energy.
Digital Repository @ Iowa State University, http://lib.dr.iastate.edu/
Sue-Lein Wang Lii
Lii, Sue-Lein Wang, "A hybrid Patterson-superposition/direct-method approach to the X-ray phase problem, and in-lab EXAFS techniques " (1985). Retrospective Theses and Dissertations. 8720.