A theoretical study of the AlC3+ species has been carried out. Predictions
have been made for some of the molecular properties (geometries, dipole mom
ents, and harmonic vibrational frequencies) which could help in their possi
ble experimental detection. In addition, a topological analysis of the elec
tron density and its associated Laplacian has also been carried out. The gl
obal ground state is predicted to be a linear species with (1)Sigma electro
nic state, but a rhombic four-membered ring ((1)A(1)) lies close in energy.
It seems that both isomers could be accessible to experimental detection.
(C) 2001 John Wiley & Sons, Inc.