  We investigate the magnetic interactions in Sr3NiPtO6, characterized to be a
spin liquid using ab initio calculations. The results reveal a novel metal to
insulator transition due to finite exchange interaction strength; the magnetic
solutions (independent of magnetic ordering) are large band gap insulators,
while the non-magnetic solution is metallic. The Ni moment is found to be large
and the coupling among intra-chain Ni moments is antiferromagnetic unlike other
compounds in this family. These results, thus, reveal the importance of
intra-chain antiferromagnetic interaction in addition to geometrical
frustration to derive spin liquid phase.
