Planar Tetracoordinate Fluorine in Binary Clusters

Planar tetracoordinate fluorine (ptF) species are rare and exotic due to the extreme electronegativity of fluorine. Herein, a planar tetracoordinate fluorine (ptF) species is predicted in the binary Li4F4− and Na4F4− clusters. The global minimum of the clusters feature C2v geometry and are stabilized by significant electrostatic interaction. Moreover, multicentre ionic bonds also play a vital role in the stability of the planar C2v geometry. The present study establishes the first example of ptF centre in binary alkali halide cluster.