High-level multireference calculations are reported for the low-lying electronic states of GaN. Using the CASSCF/MRSDCI approach and the aug-cc-pVQZ basis set a detailed analysis is given for the 22 electronic states that dissociate in the first two channels. The ground state is confirmed as (X(3)Sigma(-)) but the first excited state ((1)(3)Pi) is found to be very close in energy. A very accurate spectroscopic characterization is made for the lowest-lying triplet and singlet states. The behavior of dipole moment and transition dipole moment with internuclear distance is also described. Relative intensities are predicted using the Einstein coefficients. (c) 2005 Elsevier B.V. All rights reserved.