Electronic Structure of Muonated Me4P[Pd(dmit)2]2

Me4P[Pd(dmit)2]2 is an organic magnet that show long range antiferromagnetic ordering as indicated by Muon Spin Rotation measurements. Three muon centers were observed in the material. To determine the muon stopping sites, we have employed the Molecular Orbital Cluster Method to study the electronic structure of muonated Me4P[Pd(dmit)2]2. We used a cluster containing 1 formula unit in our investigations and applied the Density Functional Theory method. Three µ+ centers in the vicinity of three chemically non-equivalent sulfur sites, namely thione, thiol and thiolate were examined. All three µ+ sites were found to be energetically stable. In the pure Me4P[Pd(dmit)2]2 cluster, the spin densities of the doublet state system is spread throughout the entire dimer. Spin density of only about 0.13 is localized around the thiolate moiety. For all three µ+ centers, the lattice relaxation effect is important to stabilize the sites energetically.