Don't worry, there are many formulas for perovskit
Post# of 22453
Examples:
Strontium titanate
Calcium titanate
Lead titanate
Bismuth ferrite
Lanthanum ytterbium oxide
Silicate perovskite
Lanthanum manganite
Yttrium aluminum perovskite (YAP)
Lutetium aluminum perovskite (LuAP)
Solid solutions:
Lanthanum strontium manganite
LSAT (lanthanum aluminate – strontium aluminum tantalate)
Lead scandium tantalate
Lead zirconate titanate
Methylammonium lead halide