Structural Evolution and Bonding Properties of CrSi ( = 1-12) Clusters: Mass-Selected Anion Photoelectron Spectroscopy and Theoretical Calculations.

We investigated the structural characteristics and bonding properties of CrSi ( = 1-12) clusters by using anion photoelectron spectroscopy combined with density functional theory calculations. The experimental and theoretical results reveal that Cr atoms of the most stable structures of CrSi clusters with < 8 are located at the surface, while the most stable structures of CrSi clusters with ≥ 8 have one Cr encapsulated in the cage consisting of the other Cr atom and the Si atoms. The Cr-Cr interaction in the most stable structures of CrSi clusters is strong, except that the Cr-Cr interaction in the lowest lying isomer of the CrSi cluster is weak. The structure of CrSi can be viewed as the Cr surrounded by a chair-shaped silicon six-membered ring with the C symmetry. CrSi has a C symmetric antihexagonal prism structure with two Cr atoms located at the center and the surface of the Si cage, respectively. The magnetic moments of CrSi are 1 μB except that the magnetic moment of CrSi is 9 μB.