An Ab Initio Study of the Structures and Relative Stabilities of Doubly Charged [(NaCl)m(Na)2]2+ Cluster Ions

摘要

We present ab initio perturbed ion calculations on the structures andrelative stabilities of doubly charged [(NaCl)_m(Na)_2]2+ cluster ions. Theobtained stabilities show excellent agreement with experimental abundancesobtained from mass spectra. Those enhanced stabilities are found to be aconsequence of highly compact structures that can be built only for certainvalues of m. Nearly all magic number clusters can be shown to be constructed inone of the two following ways: (a) by adding tri- or penta-atomic chains to twoedges of a perfect neutral (NaCl)_n cuboid, with n=m-2 or n=m-4, respectively;(b) by removing a chloride anion from a perfect singly charged (NaCl)_nNa+cuboid, with n=m+1.