For our quantum-chemical calculations we consider four test cases that correspond to typical applications of 2D IR spectroscopy in experiment. First, we investigate the CO stretching vibrations in two metal-carbonyl complexes, dicarbonyl(acetylacetonato)rho- The first test case is the well-studied DAR molecule, which shows a prototypical 2D IR spectrum. It features two strongly-coupled anharmonic CO stretch vibrations, with an asymmetric stretch mode at ωa and a symmetric stretch mode at ωs , both of which carry strong IR intensity. These two fundamental vibrations give rise to three overtone and combination bands.