Robust atomic orbital in the cluster magnet LiMoO2

In this study, we present a rutile-related material, $\mathrm{Li}\mathrm{Mo}{\mathrm{O}}₂$, that becomes a cluster magnet and exhibits a spin singlet formation on a preformed molybdenum dimer upon cooling. Unlike ordinary cluster magnets, the atomic ${d}_yz$ orbital robustly survives despite the formation of molecular orbitals, thereby affecting the magnetic properties of the selected material. Such hybrid cluster magnets with the characters of molecular and atomic orbitals realize multiple independent spins on an isolated cluster, leading to an ideal platform to study the isolated spin dimers physics.