Bond valence analysis of the cubic perovskite SnTaO3: confirmation of its existence

The existence of the cubic perovskite phase SnTaO3 has been confirmed by using the bond valence model. The bond valence analysis of the crystal structure of SnTaO3 involved (i) evaluating the reliability of the bond valence parameters reported earlier for Sn(II)—O bonds; (ii) determining the hitherto unreported bond valence parameters for Ta(IV)—O bonds; (iii) calculating the bond valence sums for all the crystallographically different atoms in the structure; and (iv) calculating the “global instability index” of the structure. The values of the bond valence sums and “global instability index” calculated for the structure of SnTaO3 indicate the stability of this ternary phase and the plausibility of the stoichiometric perovskite structural model proposed for SnTaO3.