“…Hereinafter we address quasi-two-dimensional compound with stacked square lattice magnetic planes (CuBr)Sr 2 Nb 3 O 10 . Neutron scattering experiment [13,14] indicates helical spin order in this substance, while DMI-based explanation is unacceptable (inversion symmetry is preserved). This dyad brings forth the assumption to describe the magnetic order via J 1 − J 2 − J 3 Heisenberg model [13,14].…”