Materials Data on EuAl4 by Materials Project
EuAl4 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Eu is bonded in a 8-coordinate geometry to sixteen Al atoms. There are eight shorter (3.35 Å) and eight longer (3.57 Å) Eu–Al bond lengths. There are two inequivalent Al sites. In the first Al site, Al is bonded to four equivalent Eu and eight Al atoms to form a mixture of distorted edge, face, and corner-sharing AlEu4Al8 cuboctahedra. There are four shorter (2.67 Å) and four longer (3.09 Å) Al–Al bond lengths. In the second Al site, Al is bonded in a 9-coordinate geometry to four equivalent Eu and five Al atoms. The Al–Al bond length is 2.57 Å.