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Artículo
First-principles periodic calculation of four-body spin terms in high-Tc cuprate superconductors
(American Physical Society, 2006)
A general mapping between the energy of pertinent magnetic solutions and the diagonal terms of the spin Hamiltonian in a local representation provides the first general framework to extract accurate values for the many ...
Artículo
Local character of magnetic coupling in ionic solids
(American Physical Society, 1999)
Magnetic 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 ...
Artículo
Four-spin cyclic exchange in spin ladder cuprates
(American Physical Society, 2003)
The four-spin cyclic exchange term Jring of three spin-ladder cuprates (SrCu2O3, Sr2Cu3O5, and CaCu2O3) has been calculated from ab initio quantum chemistry calculations. For the first two compounds, a non-negligible cyclic ...
Artículo
Analysis of the magnetic coupling in binuclear complexes. II. Derivation of valence effective Hamiltonians from ab initio Cl and DFT calculations
(American Institute of Physics Publising LLC, 2002)
Most interpretations of the magnetic coupling J between two unpaired electrons rest upon simple valence models that involve essentially the ferromagnetic direct exchange contribution, Kab , and the antiferromagnetic ...
Artículo
Analysis of the magnetic coupling in binuclear systems. III. The role of the ligand to metal charge transfer excitations revisited
(American Institute of Physics Publising LLC, 2009)
In magnetic coordination compounds and solids the magnetic orbitals are essentially located on metallic centers but present some delocalization tails on adjacent ligands. Mean field variational calculations optimize this ...
Artículo
Accurate ab initio determination of magnetic interactions and hopping integrals in La2-xSrxCuO4 systems
(American Institute of Physics Publising LLC, 2000)
The nature of magnetic interactions and electron transfer processes in La22xSrxCuO4 systems are studied, by means of an ab initio embedded cluster model approach, using a difference dedicated configuration interaction ...
Artículo
Artículo
A convenient decontraction procedure of internally contracted state-specific multireference algorithms
(American Institute of Physics Publising LLC, 2006)
Internally contracted state-specific multireference MR algorithms, either perturbative such as CASPT2 or NEVPT2, or nonperturbative such as contracted MR configuration interaction or MR coupled cluster, are computationally ...
Artículo
Direct generation of local orbitals for multireference treatment and subsequent uses for the calculation of the correlation energy
(American Institute of Physics Publising LLC, 2002)
We present a method that uses the one-particle density matrix to generate directly localized orbitals dedicated to multireference wave functions. On one hand, it is shown that the definition of local orbitals making ...
Artículo
Analysis of the magnetic coupling in binuclear complexes. I. Physics of the coupling
(American Institute of Physics Publising LLC, 2002)
Accurate estimates of the magnetic coupling in binuclear complexes can be obtained from ab initio configuration interaction ~CI! calculations using the difference dedicated CI technique. The present paper shows that the ...