The A2Π- X2Σ + emission spectrum of zinc deuteride

The A²Π- X²Σ ⁺ emission of ZnD was studied at moderate and high resolution in the region 346-505 nm. A detailed rotational analysis of 10 bands has been performed using the ²Π formulas of Mulliken and Christy, with the Almy and Horsfall centrifugal distortion term. The principal molecular constants for the X²Σ ⁺ state are (cm ^-1): B_e = 3.3990, α_e = 0.0964, D_e = 1.16 × 10 ^-4, β_e = 6.4 × 10 ^-6, γ₀ = 0.122, ω_e = 1141.54, ω_ex_e = 24.29, and, for the A²Π state, T_e = 23 280.55, B_e = 3.7772, α_e = 0.0868, D_e = 1.14 × 10 ^-4, A₀ = 343.29, p₀ = 0.149, q₀ = 1.53 × 10 ^-3, ω_e = 1361.49, and ω_ex_e = 20.69. RKR potential curves and A- X Franck-Condon factors were calculated. A comparison was made with the spectrum of ZnH and the isotopic splitting for ⁶⁴ZnD, ⁶⁶ZnD, and ⁶⁸ZnD is briefly discussed.