Orientational ordering of three SiO4 tetrahedra in α″L-Ca1.5Sr0.5SiO4 that satisfies bond-valence requirements and avoids O-O repulsion

Hironori Itoh, Fumito Nishi, Takahiro Kuribayashi, Yasuhiro Kudoh

Research output: Contribution to journalArticlepeer-review

8 Citations (Scopus)


The crystal structure of α″L-Ca1.55(4)Sr0.45(4)SiO4 was analyzed by single-crystal X-ray diffraction. Refinement with isotropic temperature factors yielded R = 5.4%. The occupancies of the M(11), M(12), M(13), M(21), M(22), and M(23) sites by Sr are 0.40(3), 0.37(3), 0.42(3), 0.11(3), 0.04(2), and 0, respectively. The structure contains SiO4 tetrahedra in three different orientations. The orientational ordering of the Si(n)O4 (n = 1-3) tetrahedra accommodates the M(1n)-O (n = 1-3) bond-valence unbalances caused by the ionic radii mismatch and also avoids increasing the O-O electric repulsions between adjacent Si(n)O4 tetrahedra.

Original languageEnglish
Pages (from-to)234-240
Number of pages7
JournalJournal of Mineralogical and Petrological Sciences
Issue number4
Publication statusPublished - 2009 Aug


  • Bond-valence
  • Ionic radii mismatch
  • O-O repulsion
  • Orientational ordering
  • α″-CaSrSiO

ASJC Scopus subject areas

  • Geophysics
  • Geology

Fingerprint Dive into the research topics of 'Orientational ordering of three SiO<sub>4</sub> tetrahedra in α″<sub>L</sub>-Ca<sub>1.5</sub>Sr<sub>0.5</sub>SiO<sub>4</sub> that satisfies bond-valence requirements and avoids O-O repulsion'. Together they form a unique fingerprint.

Cite this