Where can I find data for the Madelung constants for various ionic compounds? Specifically, I am looking at silicon tetrachloride, yttrium (III) chloride, zirconium (IV) oxynitrate hydrate, niobium (V) chloride, molybdenum (V) chloride, hafnium tetrachloride, tantalum (V) chloride, and tungsten hexachloride.
Is there a database that has already-determined Madelung constants? Thanks.