FULL-POTENTIAL AB-INITIO CALCULATIONS OF SPIRAL SPIN-DENSITY WAVES INFCC FE

All ab initio calculations of spiral spin density waves heretofore hav e used the atomic sphere approximation (ASA) in which not only is the potential assumed spherical but also the direction of magnetization is taken constant within each Wigner-Seitz sphere. We have performed ful l potential local density approximation calculations for gamma-Fe spir al spin density waves with wave vector q=(2 pi/a)(0,0,alpha) and q=(2 pi/a)(gamma,0,1), finding the ground state at alpha approximate to 0.5 5. The results differ quantitatively but not qualitatively from those of ASA calculations. However, interesting results are obtained for the azimuthal angle of the magnetization phi(r)= 9.r+<(phi)over cap> (r), where e(+<(phi)over cap>(r)) is a function with the lattice periodici ty which is calculated self-consistently. [S0163-1829(98)04738-9].