The distribution of framework aluminum atoms and extraframework exchanged cations in faujasite as studied by molecular dynamics, NMR simulation, neutron diffraction simulation and computer graphics

Hiroaki Himei, Michiyuki Yamadaya, Yasunori Oumi, Momoji Kubo, Andras Stirling, Rajappan Vetrivel, Ewa Broclawik, Akira Miyamoto

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The effectiveness and applicability of molecular dynamics (MD), NMR simulation, and computer graphics to the investigation of the sites and distribution of framework aluminum atoms in faujasites, which cannot be derived from experimental techniques is shown. By using MD calculations, we successfully predicted the adequate aluminum distribution in NaY zeolite (Si/Al = 2.43), as it reproduces the sites and occupancies of Na+ cations which have been reported by neutron diffraction techniques. The validity of our aluminum distribution model in the NaY was strongly confirmed by the simulated 29Si MAS NMR spectra in agreement with the experimental chemical shifts and intensities. Although the sites and occupancies of the exchanged cations in faujasites can be determined by analytical experimental techniques, their atomistic detailed distribution cannot be derived experimentally. A methodology is proposed to predict the detailed distribution of the Na+ cations in NaY by using neutron diffraction spectrum simulation.

Original languageEnglish
Pages (from-to)235-242
Number of pages8
JournalMicroporous Materials
Issue number5
Publication statusPublished - Jan 1 1996



  • Aluminium distribution
  • Cation distribution
  • Computer graphics
  • Faujasite
  • Molecular dynamics
  • NMR simulation
  • Neutron diffraction simulation

ASJC Scopus subject areas

  • Chemistry(all)
  • Materials Science(all)
  • Engineering(all)

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