Deepest Terms in Ions of the Isoelectronic Sequences Ni I to Kr IX and Pd I to Xe IX

Radiations corresponding to the energy differences between the terms $3d^{10}{}_{}{}^1{}_{}{}^{}S_0^{}{}_{}{}^{}$ and $3d^{9}4p{{}_{}{}^3{}_{}{}^{}P_1^{}{}_{}{}^{}}^0$, ${{}_{}{}^1{}_{}{}^{}P_1^{}{}_{}{}^{}}^0{{}_{}{}^3{}_{}{}^{}D_1^{}{}_{}{}^{}}^{\circ }$ in Ge V, As VI, Se VII and Br VIII have been found. Also, the corresponding radiations, $4d^{10}{}_{}{}^1{}_{}{}^{}S_0^{}{}_{}{}^{}-4\mathrm{}{d}^{9}5p{{}_{}{}^3{}_{}{}^{}P_1^{}{}_{}{}^{}}^0$, ${{}_{}{}^1{}_{}{}^{}P_1^{}{}_{}{}^{}}^0$, ${{}_{}{}^3{}_{}{}^{}D_1^{}{}_{}{}^{}}^0$ in Sb VI, Te VII and I VIII have been observed. A new relation involving displaced frequencies has been used to predict the wave-length of the lines observed and the corresponding lines of Kr IX and Xe IX as yet not observed. A study of the ionization potentials in the sequences shows that it is possible to calculate the ionization potentials of atoms more highly ionized than those reported.