Electronic structure and exchange interactions in GdB4

• Electronic structure of AFM Shastry–Sutherland compound GB4 is calculated.
• The mechanism of exchange parameters evaluation within Heisenberg model is proposed.
• Calculated exchange parameters are found to be in agreement with experimental data.
• Higher-order exchange interactions are important for dimer structure stabilizing.

The electronic structure of the antiferromagnetic Shastry–Sutherland compound GdB4 has been analyzed with density functional theory and the all-electron full-potential linearized augmented-plane wave (FP-LAPW) code. Different magnetic configurations, including the realistic dimer one, have been considered. The exchange interactions were found to be J1/kB=−12K and J2/kB=−2–0.8K, where, J1 and J2 are the diagonal exchange interaction and the exchange interaction along the edges of a square, respectively.