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BeF2 is quartz (alpha) structured and crystallizes in the trigonal P3_121 space group. The structure is three-dimensional. Be2+ is bonded to four equivalent F1- atoms to form corner-sharing BeF4 tetrahedra. There is two shorter (1.56 Å) and two longer (1.57 Å) Be–F bond length. F1- is bonded in a bent 150 degrees geometry to two equivalent Be2+ atoms.
BeF2 is quartz (beta) structured and crystallizes in the hexagonal P6_222 space group. The structure is three-dimensional. Be2+ is bonded to four equivalent F1- atoms to form corner-sharing BeF4 tetrahedra. All Be–F bond lengths are 1.56 Å. F1- is bonded in a bent 150 degrees geometry to two equivalent Be2+ atoms.
BeF2 crystallizes in the monoclinic C2 space group. The structure is two-dimensional and consists of one BeF2 sheet oriented in the (0, 0, 1) direction. there are two inequivalent Be2+ sites. In the first Be2+ site, Be2+ is bonded in a trigonal planar geometry to three F1- atoms. There are a spread of Be–F bond distances ranging from 1.41–1.54 Å. In the second Be2+ site, Be2+ is bonded in a tetrahedral geometry to four F1- atoms. There is two shorter (1.56 Å) and two longer (1.57 Å) Be–F bond length. There are three inequivalent F1- sites. In the first F1- site, F1- is bonded in a single-bond geometry to one Be2+ atom. In the second F1- site, F1- is bonded in a linear geometry to two Be2+ atoms. In the third F1- site, F1- is bonded in a distorted bent 120 degrees geometry to two Be2+ atoms.
BeF2 crystallizes in the orthorhombic Cmmm space group. The structure is three-dimensional. Be2+ is bonded to twelve equivalent F1- atoms to form a mixture of face and edge-sharing BeF12 cuboctahedra. There are four shorter (2.40 Å) and eight longer (2.41 Å) Be–F bond lengths. F1- is bonded in a 11-coordinate geometry to six equivalent Be2+ and five equivalent F1- atoms. There are three shorter (2.06 Å) and two longer (2.48 Å) F–F bond lengths.