title: Hexagonal Frank--Kasper phases interpreted as modulated crystals.
abstract: The structures of the hexagonal Frank--Kasper phases F and K, which have been described in terms of the aggregation of clusters, are interpreted as modulated crystal structures. They are basically composed of two close-packed layers with ordered atomic vacancies rotated by 90 degrees to each other about their normal.
authors.affiliation: Advanced Materials Laboratory, National Institute for Materials Science, Tsukuba, Ibaraki, 305-0044, Japan. uchida.masaya@nims.go.jp
authors.forename: M
authors.initials: M
authors.lastname: Uchida
authors.forename: Y
authors.initials: Y
authors.lastname: Matsui