  The magnetic structure of the edge sharing cuprate compound Li2CuO2 has been
investigated by means of ab initio electronic structure calculations. The first
and second neighbor in-chain magnetic interactions are calculated to be -142 K
and 22 K, respectively. The ratio between the two parameters is smaller than
suggested previously in the literature. The interchain interactions are
antiferromagnetic in nature and of the order of a few Kelvins only. Monte Carlo
simulations using the ab initio parameters to define the model Hamiltonian
result in a Neel temperature in rather good agreement with experiment. Spin
population analysis situate the magnetic moment on the copper and oxygen ions
somewhere between the completely localized picture derived from experiment and
the more delocalized picture based on local density calculations.
