Notes. From left to right, we list the atom species, transition wavelength, the dominant configuration and term designation for the lower and upper levels, the energy of the lower level, the series limit energy for that level, the energy of the upper level, the series limit energy for that level, the orbital angular momentum quantum numbers of the optical electron in the lower and upper levels, the total angular momentum quantum numbers of the lower and upper levels, and finally the calculated line broadening cross-section σ due to hydrogen atom impact at a collision velocity of 10⁴ m s⁻¹ and corresponding velocity dependence parameter α. The units for the wavelength are Å, the energy is listed in cm⁻¹, and atomic units for the cross-section σ, respectively. The velocity parameter α is dimensionless.