  Ultraviolet and visible spectra of the symbiotic nova RR Telescopii are used
to derive reference wavelengths for many forbidden and intercombination
transitions of ions +1 to +6 of elements C, N, O, Ne, Na, Mg, Al, Si, P, S, Cl,
Ar, K and Ca. The wavelengths are then used to determine new energy values for
the levels within the ions' ground configurations or first excited
configuration. The spectra were measured by the Space Telescope Imaging
Spectrograph of the Hubble Space Telescope and the UltraViolet Echelle
Spectrograph of the European Southern Observatory in 2000 and 1999,
respectively, and cover 1140 to 6915 A. Particular care was taken to assess the
accuracy of the wavelength scale between the two instruments. An investigation
of the profiles of the emission lines reveals that the nebula consists of at
least two plasma components at different velocities. The components have
different densities, and a simple model of the lines' emissions demonstrates
that most of the lines principally arise from the high density component. Only
these lines were used for the wavelength study.
