  We have calculated the ground state spectroscopic constants and the molecular
properties, of a molecular ion BeLi + , such as dipole moment, quadrupole
moment and dipole polarizability at different levels of correlation: many-body
perturbation theory (MP2), coupled cluster method with single and double
excitations (CCSD) and CCSD with perturbative triples (CCSD(T)). The
correlation consistent polarized valence cc-pVXZ (X=D, T, Q) basis sets and
also their augmented counterparts are used together with the non-relativistic
and relativistic Hamiltonians. The results are extrapolated to the complete
basis set limit (CBS) using exponential-Gaussian function. Thus, accurate and
reliable results for BeLi + with the most conservative error estimates on them
are reported.
