Tetragonal In2ZrBr6, a slightly distorted variant of the K2PtCl6 struc
ture type, contains almost cubotachedral InB1211- units that are shari
ng trigonal faces with ZrBr62- complex anions. In2ZrBr6 is a weak van
Vleck-type paramagnet, and we propose that this behavior originates fr
om an indirect electronic coupling between occupied bands with strong
indium 5s character and unoccupied, fairly localized zirconium 4d crys
tal orbitals, moderated by bridging Br- anions. In+ is weakly and nond
irectionally bonded to coordinating Br- (there is an almost insignific
ant indium 5p bonding contribution) and the crystal potential around I
n+ turns out to be very soft because of antibonding In+-Br- interactio
ns within the highest occupied bands.