Spectrum of doubly ionised indium

The emission spectrum of indium has been photographed over the spectral range from 340 to 6500 AA using a disruptive electrodeless discharge and a spark in helium as sources. The analysis of In III has been revised and extended and now includes 4d¹⁰ns (n=5 to 12), 4d¹⁰np (n=5 to 9), 4d¹⁰nd (n=5 to 9) and 4d¹⁰nf (n=4 to 7). Polarisation theory has been applied to the 4d¹⁰ng (n=5 to 9) and 4d¹⁰nh (n=6 to 9) series and the ionisation potential deduced to be 226191 cm^-1. The dipole polarisability of the 4d¹⁰ core is estimated to be 3.45 a₀³. Most of the expected terms of 4d⁹5s5p are established for the first time.