Calculations of Configurations of Doubly Ionized Copper (Cu III)

The energy levels belonging to the configurations 3d 74s 2 and 3d 8 nℓ (nℓ = 4s, 5s, 4p 5p, 4d 5d 4f, and 5g) have been calculated. The radial energy integrals were treated as parameters and adjusted to give a least-squares fit to the observed levels. Two- and three-body effective electrostatic interactions for equivalent electrons were included, as well as two-body effective interactions for inequivalent electrons. Strong configuration interaction between 3d 74s 2 and 3d 84d was taken into account. Values of the parameters are given for all the above configurations, and the calculated levels are given for all except 3d 84s and 3d 84p (for which essentially equivalent results have been published). Leading eigenvector percentages are given in appropriate coupling schemes.

The Third Spectrum of Copper (Cu iii)

An analysis of Cu iii based on observations from 500 to 6900 Å is presented. The low structures 3d 9 and 3d 84s are complete, including the rarely, if ever before, found 3d 8(1S)4s 2S. The 3d 74s 2 includes 4F, 2F, 2G, and 2H but the 4P, 2P, a 2D, b 2D have eluded all attempts to find them. The ionization potential calculated from 4s, 5s, 6s 44 F 4 1 / 2 is 296 980 cm-1 but by a comparison with Ni II which has a longer series an approximate value of 297 140 can be estimated. The 3d 84d group is complete, except for one level, as is 5dbased on 3F and 1G, the other 5d groups being incomplete. 3d 8(3F)4f is complete and 26 levels based on 1D, 3P, 1G are known. 3d 8(3F)5g is incomplete and a few levels based on 1D and 1G have been found. A discussion of the validity of the analysis of Cu iv by J. F. Schröder and Th. A. M. Van Kleef is given.