title: O8 cluster structure of the epsilon phase of solid oxygen.
abstract: Despite many experimental and theoretical studies, the crystal structure of the epsilon phase of solid oxygen has not been determined. We performed powder x-ray diffraction experiments and the Rietveld analyses in this study to show that a new arrangement of the monoclinic space group C2/m could fit the diffraction patterns of the epsilon phase and obtained a structure that consisted of an O8 cluster with 4 molecules. The dependence of the lattice parameters, the molar volume, and the intermolecular distances on the pressure was investigated.
authors.affiliation: National Institute of Advanced Industrial Science and Technology (AIST), AIST Tsukuba Central 5, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Fujihisa
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Akahama
authors.forename: Haruki
authors.initials: H
authors.lastname: Kawamura
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Ohishi
authors.forename: Osamu
authors.initials: O
authors.lastname: Shimomura
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Yamawaki
authors.forename: Mami
authors.initials: M
authors.lastname: Sakashita
authors.forename: Yoshito
authors.initials: Y
authors.lastname: Gotoh
authors.forename: Satoshi
authors.initials: S
authors.lastname: Takeya
authors.forename: Kazumasa
authors.initials: K
authors.lastname: Honda