An effective Hamiltonian is constructed for an insulating cuprate with
edge-sharing chains Li2CuO2.The Hamiltonian contains the nearest and
next-nearest neighboring intrachain and zigzag-type interchain interactions.The
values of the interactions are obtained from the analysis of the magnetic
susceptibility, and this system is found to be described as coupled frustrated
chains.We calculate the dynamical spin correlation function S(q,\omega) by
using the exact diagonalization method, and show that the spectra of
S(q,\omega) are characterized by the zigzag-type interchain interactions. The
results of the recent inelastic neutron scattering experiment are discussed in
the light of the calculated spectra.Comment: 4 pages, 3 figures, RevTe