A local spin-density study of antiferromagnetism in La2CuO4and YBa2Cu3O6

Abstract
The authors present local spin-density (LSD) calculations for YBa2Cu3O6 and La2CuO4. They find YBa2Cu3O6 to be an antiferromagnetic semimetal with a very small or nearly nonexistent moment. The value of this moment is not only dependent on the Brillouin zone integration sampling, but is also sensitive to the angular momentum expansion of the Cu and O sites in the CuO2 layers. Expanding (or squeezing) the Wigner-Seitz spheres up to 10% (or down to 9%) or including the breathing mode failed to make La2CuO4 an antiferromagnetic semiconductor.