Abstract
A number of band systems attributed to ScF have been observed both in absorption and in thermal emission at high temperatures (similar 2000 °c). Rotational analyses have been made of bands of four singlet systems. These systems all appear in absorption, and the lower state × 1Σ is probably the lowest singlet state of ScF. Bands of more complex appearance, perhaps arising from triplet transitions, are also observed in absorption, so that the nature of the ground state is not yet established. The value of the internuclear distance r0 in × 1Σ is 1.791 Å.