*Theoretical charge density distributons were calculated by using LAPW method program 'WIEN97'.
(P.Blaha, K.Schwarz and J.Luitz, WIEN97, A Full Potential Linearized Augmented Plane Wave Package for Calculating Crystal Properties, (Karlheinz Schwarz, Techn. Univ. Wien, Vienna 1999). ISBN 3-9501031-0-4)