  The recently proposed many-body expanded full configuration interaction
(MBE-FCI) method is extended to excited states and static first-order
properties different from total, ground state correlation energies. Results are
presented for excitation energies and (transition) dipole moments of two
prototypical, heteronuclear diatomics---LiH and MgO---in augmented correlation
consistent basis sets of up to quadruple-$\zeta$ quality. Given that MBE-FCI
properties are evaluated without recourse to a sampled wave function and the
storage of corresponding reduced density matrices, the memory overhead
associated with the calculation of general first-order properties only scales
with the dimension of the desired property. In combination with the
demonstrated performance, the present developments are bound to admit a wide
range of future applications by means of many-body expanded treatments of
electron correlation.
