Materials Data on LaAlSi2 by Materials Project
LaAlSi2 crystallizes in the trigonal P-3m1 space group. The structure is three-dimensional. La is bonded in a 12-coordinate geometry to nine Si atoms. There are a spread of La–Si bond distances ranging from 3.14–3.24 Å. Al is bonded to four equivalent Si atoms to form a mixture of edge and corner-sharing AlSi4 tetrahedra. There are three shorter (2.51 Å) and one longer (2.58 Å) Al–Si bond lengths. There are two inequivalent Si sites. In the first Si site, Si is bonded in a 7-coordinate geometry to three equivalent La and four equivalent Al atoms. In the second Si site, Si is bonded in a 9-coordinate geometry to six equivalent La and three equivalent Si atoms. All Si–Si bond lengths are 2.42 Å.
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