  Motivated by possible astrophysical and biological applications we calculate
visible and near UV spectral lines of proflavine (C13H11N3,
3,6-diaminoacridine) in vacuum, as well as its anion, cation, and dication. The
pseudopotential density functional and time-dependent density functional
methods are used. We find a good agreement in spectral line positions
calculated by two real-time propagation methods and the Lanczos chain method.
Spectra of proflavine and its ions show characteristic UV lines which are good
candidates for a detection of these molecules in interstellar space and various
biological processes.
