Related Experiment Video
Updated: Aug 23, 2026

Curation of Computational Chemical Libraries Demonstrated with Alpha-Amino Acids
Published on: April 13, 2022
Solving the Sayre equations for centrosymmetric structures with a genetic algorithm
1Department of Physics and Texas Center for Superconductivity and Advanced Materials, University of Houston, 77204, USA.
Abstract:
Sayre's equations give a set of relationships that exist among the structure factors of an equal-atom structure. In order to obtain the correct phases of the structure factors, a genetic algorithm is used to minimize a least-squares residual of Sayre's equations. In the genetic algorithm, a phase is treated as a gene and the whole set of phases is considered as a chromosome. Every chromosome is relaxed to a nearby local minimum by quenching after being produced from a previous generation. Trial calculations for a structure containing 92 non-H equal atoms with synthetic data and another structure containing 62 non-H equal atoms with real data are presented. Compared to simulated annealing, a genetic algorithm is a more efficient means of global optimization.
Related Concept Videos
Centroid of a Body: Problem Solving
The x-coordinates and y-coordinates of each element's...
Predicting Molecular Geometry
Molecules with Multiple Chiral Centers
Determination of Crystal Structures
Gaussian Elimination: Problem Solving
Stereoisomerism of Cyclic Compounds

