Dipole-bound states of the alkali–superhalogen anions: (X = F, Cl, Br)

The dipole-bound states of the LiBeX 3 - (X = F, Cl, Br) anions were predicted at the MP2/aug-cc-pVDZ+5s5p level of theory. Upon electron attachment, the neutral LiBeX3 host shows noteworthy geometrical relaxation, which is accompanied by a significant increase of the dipole moment. The LiBeX 3 - anions exhibit large vertical electron detachment energies of 539.2–886.5 MeV at the CCSD(T)/aug-cc-pVDZ+6s6p4d level, indicating that the binding of electrons to the alkali–superhalogen LiBeX3 molecules is feasible. In addition, the stabilities of the LiBeX 3 - anions with respect to the neutral hosts, are found to be closely related to the electronegativity of the X ligands and partial atomic charge localized on Be.