Fingerprints of antiaromaticity in the negative ion (Li$_3$Al$_4$)$^-$   via an ab initio quantum-chemical study of the equilibrium structure of the   inhomogeneous electron liquid
  Fingerprints of antiaromaticity in the negative ion (Li$_3$Al$_4$)$^-$, this species being realizable via a laser vaporization technique, are revealed by means of an \emph{ab initio} quantum-chemical investigation. First, the ground-state equilibrium geometry of this ion is predicted. Also, for the corresponding inhomogeneous electron liquid, the characteristics of the HOMO are studied, both for the square and the rectangular Al$_4$ geometry in two low-lying isomers of the negative ion. There is no particular sensitivity to the change in geometry of the Al$_4$ configuration. Therefore, we have calculated theoretically chemical shifts (NICS), which contain remarkable fingerprints of antiaromaticity. As to future directions, some comments are added in relation to the Shannon entropy. 
A. Grassi, G. M. Lombardo, G. G. N. Angilella, N. H. March, R. Pucci,   D. J. Klein, A. T. Balaban
physics.chem-ph cond-mat.other