  Hypothetical metals having optical absorption losses as low as those of the
transparent insulators, if found, could revolutionize optoelectronics. We
perform the first high-throughput search for lossless metals among all known
inorganic materials in the databases of over 100,000 entries. The 381
candidates are identified -- having well-isolated partially-filled bands -- and
are analyzed by defining the figures of merit and classifying their real-space
conductive connectivity. The existing experimental evidence of most candidates
being insulating, instead of conducting, is due to the limitation of current
density functional theory in predicting narrow-band metals that are unstable
against magnetism, structural distortion, or electron-electron interactions. We
propose future research directions including conductive oxides, intercalating
layered materials, and compressing these false-metal candidates under high
pressures into eventual lossless metals.
