ELECTRONIC-STRUCTURE OF ND2CUO4 AND ITS PHYSICAL-PROPERTIES

In order to clarify the electronic structure of the electron-doped sup erconducting material Nd2-xMxCuO4, we have performed a first-principle band structure calculation for the matrix material Nd2CuO4. We find t hat doped electrons can be accommodated in both the Cu 4s and 4p(z) co nduction bands provided that the Cu 3dx2 - y2 band splits into two ban ds, i.e., the upper and lower Hubbard bands by the strong correlation. Based on this electronic structure, we have calculated the Hall coeff icient of the Nd system and have shown for the first time that the sig n of the Hall coefficient is negative, coinciding with the experimenta l result in the low-concentration case. In the overdoped region above x = 0.18, the dopant electrons occupy not only 4s and 4p(z) bands but also the upper Hubbard dx2 - y2 so that the Hall coefficient changes i ts sign from negative to positive.