NOVELTY - A crystalline inorganic compound is capable of conducting carrier chosen from anion, cation, proton, electron, and hole, and several cation-anion-containing octahedrons (I) capable of carrying out corner share into crystal structure mutually. The crystalline inorganic compound has mutually interchanging irreducible lattice constant (ar) of 5.06 plus minus 0.5 Angstrom in a-axis, irreducible lattice constant (br) of 9.61 plus minus 0.5 Angstrom in b-axis, irreducible lattice constant (cr) of 9.61 plus minus 0.5 Angstrom in c-axis, and angle (( alpha )r) of 74.31 plus minus 10 degrees .    USE - Crystalline inorganic compound. Uses include but are not limited to solid electrolyte of fuel cell, electrode of battery, oxygen enricher, deoxygenation membrane, oxygen-permeating membrane, catalyst, photocatalyst, electrical/electronic and communication apparatus, energy and environmental-related apparatus, optical instrument, etc.    ADVANTAGE - The crystalline inorganic compound has excellent electrochemical stability and high ionic conductivity.    DETAILED DESCRIPTION - A crystalline inorganic compound is capable of conducting carrier chosen from anion, cation, proton, electron, and hole, and several cation-anion-containing octahedrons of formula: (B'X6) (I) capable of carrying out corner share into crystal structure mutually. The crystalline inorganic compound has mutually interchanging irreducible lattice constant (ar) of 5.06 plus minus 0.5 Angstrom in a-axis, irreducible lattice constant (br) of 9.61 plus minus 0.5 Angstrom in b-axis, irreducible lattice constant (cr) of 9.61 plus minus 0.5 Angstrom in c-axis, angle (( alpha )r) of 74.31 plus minus 10 degrees for forming b-axis and c-axis of irreducible lattice, angle (( beta )r) of 75.63 plus minus 10 degrees for forming a-axis and c-axis of irreducible lattice, and angle (( gamma )r) of 75.63 plus minus 10 degrees for forming a-axis and b-axis of irreducible lattice. At least one of irreducible lattice constants is m/n twice the prescribed numerical value of irreducible lattice constants, where m and n are natural number, square root of 2 or 3, or integral multiple.    B'=cation of B-site;and    X=anion.