The ground state electronic structure and optical spectra of Ce(III), Ce(IV), and Eu(III) bis(octaethylporphyrin) (double deckers) are examined using the intermediate neglect of differential overlap (INDO/S) model and multireference configuration interaction (MRCI). The low-energy electronic exited states of the bisporphyrin are interpreted in terms of their monoporphyrin contributions, and the charge transfer and excitonic character of the transitions are analyzed. Particular attention is focused on the nature of the near infrared (NIR) band that characterizes the spectra of the electron deficient bisporphyrin complex, justifying its shift to higher energy as the ionic radius of the central ion decreases and relating its broadness to the contribution of closely spaced electronic transitions that become allowed through vibronic coupling. The influence of an electric perturbation on the dimeric Ce(IV) and Eu(LEI) structures is investigated and related to their conductivity. The results are compared to those derived from resonant Raman spectroscopy, which show the importance of the vibrational fine structure in the assignment of the NIR band.