A detailed study of the structure, infrared, and electronic spectra of the mixed-metal group 7 carbonyls MnTc(CO)(10), MnRe(CO)(10), and TcRe(CO)(10) is presented using density functional theory, and time-dependent density functional theory, with a variety of modern density functionals. Long-range corrected density functionals are needed to accurately model the transitions in such complexes, and through calibration with data for known bimetallic carbonyls, DFT and TD-DFT can be used to predict the behavior of their as yet elusive counterparts.