A Metropolis Monte Carlo algorithm for merging single-particle diffraction intensities

B. R. Mobley, K. E. Schmidt, J. P.J. Chen, R. A. Kirian

Research output: Contribution to journalArticlepeer-review

1 Scopus citations


Single-particle imaging with X-ray free-electron lasers depends crucially on algorithms that merge large numbers of weak diffraction patterns despite missing measurements of parameters such as particle orientations. The expand-maximize-compress (EMC) algorithm is highly effective at merging single-particle diffraction patterns with missing orientation values, but most implementations exhaustively sample the space of missing parameters and may become computationally prohibitive as the number of degrees of freedom extends beyond orientation angles. This paper describes how the EMC algorithm can be modified to employ Metropolis Monte Carlo sampling rather than grid sampling, which may be favorable for reconstruction problems with more than three missing parameters. Using simulated data, this variant is compared with the standard EMC algorithm.

Original languageEnglish (US)
Pages (from-to)200-211
Number of pages12
JournalActa Crystallographica Section A: Foundations and Advances
StatePublished - May 1 2022


  • XFEL
  • coherent X-ray diffractive imaging (CXDI)
  • molecular orientation determination
  • single particles

ASJC Scopus subject areas

  • Structural Biology
  • Biochemistry
  • General Materials Science
  • Condensed Matter Physics
  • Physical and Theoretical Chemistry
  • Inorganic Chemistry


Dive into the research topics of 'A Metropolis Monte Carlo algorithm for merging single-particle diffraction intensities'. Together they form a unique fingerprint.

Cite this