Moreira, Ibério de Pinho RibeiroIllas i Riera, FrancescCalzado, C. J.Sanz, J. F.Malrieu, J. P.Ben Amor, N.Maynau, D.2010-01-222010-01-2219990163-1829https://hdl.handle.net/2445/10840Magnetic interactions in ionic solids are studied using parameter-free methods designed to provide accurate energy differences associated with quantum states defining the Heisenberg constant J. For a series of ionic solids including KNiF3, K2NiF4, KCuF3, K2CuF4, and high- Tc parent compound La2CuO4, the J experimental value is quantitatively reproduced. This result has fundamental implications because J values have been calculated from a finite cluster model whereas experiments refer to infinite solids. The present study permits us to firmly establish that in these wide-gap insulators, J is determined from strongly local electronic interactions involving two magnetic centers only thus providing an ab initio support to commonly used model Hamiltonians.4 p.application/pdfeng(c) The American Physical Society, 1999Materials magnèticsPropietats magnètiquesFísica de l'estat sòlidMagnetic propertiesSolid state physicsMagnetic materialsinfo:eu-repo/semantics/article142175info:eu-repo/semantics/openAccess