[en] The problem of describing all N(N-1)/2 states in two-magnon sector of 1D periodic S = 1/2 chain with the Hamiltonian H = -1/2ΣNj≠lρ(j - l)(σjσl-1)/2 of spin interaction via elliptic Weierstrass ρ function is investigated. It is proved that the set of eigenvectors having Hermite-like form is complete. (author). 9 refs