  We consider a system where structural polymorphism suggests the possible
existence of superconductivity through the implied structural instability.
SrPd2Bi2 has two poly-morphs which can be controlled by the synthesis
temperature: a tetragonal form (CaBe2Ge2-type) and a monoclinic form
(BaAu2Sb2-type). Though the crystallographic difference between the two forms
may at first seem trivial, we show that tetragonal SrPd2Bi2 is superconducting
at 2.0 K whereas monoclinic SrPd2Bi2 is not. We rationalize this finding and
place it in context with other 1-2-2 phases
