Two-leg spin ladder model for Ag2VOP2O7 from mapping analysis based on first principles density functional calculations

The magnetic properties of Ag2V OP2O7 were examined by evaluating its spin exchange interactions in terms of spin dimer analysis based on tight binding calculations and mapping analysis based on first principles density functional theory calculations. Both calculations show that a strong spin exchange interaction occurs through the super-superexchange path J1 with the V…V distance of 5.293 Å. This strong antiferromagnetic interaction forms isolated spin dimer units, which are coupled antiferromagnetically by the spin exchange path J3 to form a two-leg spin ladder that has no spin frustration. The inter–dimer interaction J2 is found to be ferromagnetic, and does not lead to spin frustration.