Development of differential evolution algorithms applied to crystal structure solution from powder diffraction data

by Bell, Duncan

Type Thesis
Rate 0.0 /5

An understanding of the crystal structure can aid in the rationalisation of physicochemical properties exhibited by a crystalline material. Advances in the area of direct space crystal structure solution means that it is becoming easier to determine crystal structures from powder diffraction data. However, due to the number of structural models generated during structure solution calculations, direct space methods are computationally demanding. Work presented in this thesis reports the optimisa…

Read More ↓

Summary

An understanding of the crystal structure can aid in the rationalisation of physicochemical properties exhibited by a crystalline material. Advances in the area of direct space crystal structure solution means that it is becoming easier to determine crystal structures from powder diffraction data. However, due to the number of structural models generated during structure solution calculations, direct space methods are computationally demanding. Work presented in this thesis reports the optimisation of a differential evolution (DE) algorithm and a cultural differential evolution (CDE) algorithm to reduce the computational demands of direct space methods. Characteristics particular to certain crystal structures are identified as having a significant effect on the efficiency and robustness of structure solution calculations by DE and CDE. The development of a new algorithm that closely mimics the natural evolution of a species is discussed. Results presented in this thesis demonstrate that this new algorithm is significantly more efficient than the DE algorithm. Despite the complexity of powder diffraction patterns recorded for biphasic crystalline materials, in this thesis, the successful development and application of a direct space method to the simultaneous structure solution of two crystals from a biphasic powder pattern is reported.

Read More ↓

Edition Statements

  • Publication Date:2012

Thesis Information

  • Degree:Ph.D.
  • University:University of Birmingham

Publication Statements

  • Language:eng
  • Publication Date:2012

Edition Identifiers

  • ethos:566120

Subjects

Writers

Rate & Review

0.0/5
(0 people Voted)

No reviews yet. Be the first to rate this work.

Files & Downloads