Abstract
The 5snd 3D1 and 3D3 series of Sr are analysed by means of multi-channel quantum defect theory for principal quantum numbers n > 12. With a two-channel analysis using the 4dns configuration as second channel the admixture of 4d6s 3D1 and 3D3 character into the two 5snd J = 1 and J = 3 series is determined.