The fifth spectrum of gold (Au V): analysis of the (5d7+5d66s)-5d66p transition array

The spectrum of four times ionized gold (Au V) was investigated in the 350-1750 A wavelength region. The previous analysis of the 5d7 - 5d66p transition array has been confirmed and extended by adding 477 newly identified lines to 344 already published. The 5d66s - 5d66p transitions have been identified and 1012 spectral lines have been classified as belonging to this array. All 19 previously established levels of the 5d7 configuration and 115 levels of the 5d66p configuration have been confirmed but their energy values have been slightly corrected. Forty nine new levels belonging to the 5d66p configuration have been established giving totally 164 out of 180 theoretically possible levels. In the 5d66s configuration 49 levels, out of 63 theoretically possible, have been found. The total list of classified lines in Au V, including 344 lines identified before, is given and it contains 1833 entries. The list of known and predicted levels and their LS-percentage of the 5d7, 5d66s and 5d66p configurations in Au V is presented. Theoretical description (fitting) of these three configurations is given in the frame of the orthogonal operator approach. (orig.)