Germanide phosphides or phosphide germanides or germanophosphides are compounds containing anions composed of germanide (Ge4−) and phosphide (P3−). They can be considered as mixed anion compounds. They are distinct from the phosphidogermanates, which have the phosphorus bonded to the germanium. Related compounds include the phosphide carbides, silicide phosphides, nitride germanides, and antimonide germanides.
One preparation method is to heat a metal phosphide with germanium in a silica tube. Phosphorus must be prevented from evaporating. Another method is to use a liquid tin flux.