Absorption spectra of Zn i and Cd i in the 1300–1750 Å region

The high-dispersion absorption spectra of Zn i and Cd i have been photographed in the ~1300–1750 Å region. Observations include the principal-series transitions $m{s}^2\hspace{0.17em}{}^{1}S-msnp\hspace{0.17em}{{}^{1}P}_1^{°}$, the electric-quadrupole transitions ms^{2 1}S–msnd ¹D₂, and the intercombination transitions $m{s}^2\hspace{0.17em}{}^{1}S-msnp\hspace{0.17em}{{}^{3}P}_1^{°}$ (m = 4 and 5 for zinc and cadmium, respectively). Energy levels are presented for $msnp\hspace{0.17em}{{}^{1}P}_1^{°}\hspace{0.17em}(m<n\le 66)$, msnp ¹D₂ (m = 4 < n ≤ 20 for Zn i and m = 5 < n ≤ 26 for Cd i) and $msnp\hspace{0.17em}{{}^{3}P}_1^{°}$ (m = 4 < n ≤ 12 for Zn i and m = 5 < n ≤ 31 for Cd i). The ionization potentials of Zn i and Cd i determined from the $msnp\hspace{0.17em}{{}^{1}P}_1^{°}$ series are 75769.33 ± 0.18 cm⁻¹ and 72540.07 ± 0.18 cm⁻¹, respectively. At high metal-vapor pressures in the presence of argon, diffuse satellite lines appeared with the strong atomic transitions.