Magnetic symmetry and hyperfine fields of V4 tetrahedral clusters in the multiferroic lacunar spinel GeV4S8RemoveTh. Gimpel, N. Büttgen, L. Prodan, V. Tsurkan, A. A. Tsirlin, H. Nakamura, and I. KézsmárkiPhys. Rev. B 114, 154418 (2026)
