Large-scale SCF CI calculations have been performed for the ground 1Σ+ state of linear SiCC. The calculation includes up to quadruple excitations in the valence space plus all single and double excitations from the valence localized orbitals of the single HF configuration. Vibrational wavefunctions have been derived from the CI potential surface. Vibrational frequencies including anharmonicity corrections are calculated together with the zero-point vibrational correction to the rotational constant. The large dipole moment, 4.62 D, should make this molecule suitable for radioastronomic searches. © 1984.