Ab initio configuration interaction calculations have been performed for the X (1)Sigma(+) and B (1)Sigma(+) electronic states of LiCl. Potential energy curves, dipole moment functions, and dipole transition moments have been computed for internuclear distances between R=2.5a(0) and 50a(0). Single- and double-excitation configuration interaction wave functions were constructed using molecular orbitals obtained from a two-state averaged multiconfiguration self-consistent-field calculation. This procedure yielded an accurate energy splitting between the covalent and ionic separated-atom limits. The calculated avoided crossing of the X and B state curves occurs at R=16.2a(0), in close agreement with previous calculations using a semiempirical covalent-ionic resonance model. X (1)Sigma(+) state spectroscopic constants are in excellent agreement with experimental values. (C) 2004 American Institute of Physics.