In search of theoretically predicted magic clusters: Lithium-doped aluminum cluster anions

Lithium-doped aluminum cluster anions, LiAln- were generated in a laser vap orization source and examined via mass spectrometry and anion photoelectron spectroscopy (n=3-15). The mass spectrum of the LiAln- series exhibits a l ocal minimum in intensity at n=13. The electron affinity vs cluster size tr end also shows a dip at n=13. Agreement is quite good between our measured electron affinity values and those calculated by Rao, Khanna, and Jena, sug gesting that their predictions about the structure and bonding of LiAl13 an d other clusters in this series are also largely valid. (C) 2001 American I nstitute of Physics.