Knowledge Bank

Ab initio SCF + CI calculations of the electronic structure and properties of the lowest $\mathrm{<mrow\; data-mjx-texclass="ORD">1</mrow>}\Sigma$ and $\mathrm{<mrow\; data-mjx-texclass="ORD">1</mrow>}\Pi$ states of CO are described. The calculations utilized 48 Slater type orbitals in the basis set to describe $20\sigma$, $12\Pi$, and $10\delta$ molecular orbitals. Approximately 12 000 spin-adapted configurations are considered in the CI calculations. The calculated ground state properties include the dissociation energy as well as the variation of the dipole moment for internuclear separations between 1.80 and 10.0 Bohr (radii). Einstein A coefficients, $A_{v}^{\prime} $v, for transitions between ground state energy levels derived from the theoretical dipole moment curve are also reported. The sum of the squares of the electronic transition moments, $\Sigma |Re|2$, for the $X1\Sigma +-A1\Pi$ transition (Fourth Positive system) as a function of internuclear separation is given. In addition, calculated values of $\Sigma |Re|2$ for transitions between the ground state and excited states of $\mathrm{<mrow\; data-mjx-texclass="ORD">1</mrow>}\Sigma +$ symmetry are described.