We investigate the structural evolution and electronic properties of medium-sized silicon cluster anions doped with two transition metal atoms, TM2Sin− (TM=V, Cr; n = 14–20), by using mass-selective anion photoelectron...

The entire ground state potential energy curve of the strontium dimer is accurately described by the Tang-Toennies potential model defined by the three dispersion coefficients and two well parameters. The predicted vibrational frequency, anharmonicity, and vibration-rotation coupling constant are in excellent agreement with experiment. The Sr(2) reduced potential is almost identical to that of Ca(2) and Hg(2), providing further evidence to the conjecture that the van der Waals dimer potentials of group IIA and group IIB elements have the same shape, which is different from that of rare-gas dimers. The potentials of Sr-RG complexes (RG=He,Ne,Ar,Kr,Xe) are generated by the same potential model with its parameters calculated with combining rules. These potentials are shown to have the same shape which is between that of the strontium and rare-gas dimers.

CrSi n − (n = 14−18) cluster anions have been investigated by a combination of photoelectron spectroscopy (PES) and first-principles calculations. The lowest-lying structures of the clusters have been determined by a global minimum search based on the genetic algorithm, combined with density functional theory (DFT) calculations. The simulated PES spectra of the lowestenergy isomers are in agreement with the experimental results, which gives strong evidence that the correct structures have been found. While sizes n = 14 and n = 15 prefer cage-like structures based on multi-center bonding within the cage, the larger sizes adopt structures based on fullerene-type cages around the Cr atom, with the additional atoms attached to the cage surface. A Hirshfeld analysis shows that the Cr atoms act as electron donors in all clusters, thus enhancing the electron count in the cage. It also reveals that the magnetic moment of 1μ B shown by all clusters is mainly contributed by the Cr atom. One interesting exception is size 17, where the Cr atom contributes a small moment antiparallel to that of the silicon cage.

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We present a systematic study of the structures and electronic properties of vanadium-doped silicon cluster anions, VSin− (n=14–20), by combining photoelectron spectroscopy (PES) measurements and density functional theory (DFT) based...