(IUCr) Crystallography Journals Online

Acta Cryst. (2007). E63, i195 [ doi:10.1107/S160053680705413X ]

YMgGa

M. Sahlberg, T. Gustafsson and Y. Andersson

Abstract: The crystal structure of YMgGa, yttrium magnesium gallide, is isotypic with LaMgGa and crystallizes in the hexagonal ZrNiAl type structure. It consists of a three-dimensional network of Mg and Ga atoms, in which Y atoms fill channels. There are two crystallographically independent Ga sites. One Ga atom (Ga1) has three Mg atoms as near neighbours and six Y atoms at a slightly longer distance, giving rise to a [3 + 6] coordination. Another Ga atom (Ga2) is also nine-coordinate but has six near Mg neighbours and three Y at a somewhat longer distance in a [6 + 3] coordination. The Mg atom is tetrahedrally coordinated by four Ga atoms and has two additional Mg neighbours at a slightly longer distance. The site symmetries for Y, Ga1, Ga2 and Mg are m2m, $\\overline{6}$ , $\\overline{6}$ 2m and m2m, respectively. The crystal used was an inversion twin.

Online 14 November 2007