The mixing of the 4f^{2 1}S₀ state with the 4f5d states in Pr³⁺ doped SrAl₁₂O₁₉

The ¹S₀ state of Pr³⁺ in SrAl₁₂O₁₉ lies near to the 4f5d band. The admixing of the opposite parity 5d components by the crystal field without a symmetry center can be significant, thus affecting the properties of the ¹S₀ state. In a crystal with D_3h symmetry, the major 4f5d components which can be mixed into ¹S₀ are 2^-1/2(|fdΓ₁¹F₃ 3〉-|fdΓ₁¹F₃-3〉) and 2^-1/2(|fdΓ₁¹H₅ 3〉-|fdΓ₁¹H₅-3〉). A calculation of the 4f5d wavefunctions indicates that the states which may be mixed into ¹S₀ lie mainly at the middle and upper parts of the 4f5d configuration. The mixed 4f^{2 1}S₀ wavefunction is then calculated and its spectral properties are discussed.