Dear all, I am working on bulk multiferroic, BiFeO3. It is suppose to have a spontaneous polarization around 100 mC/cm^2 along [111] direction . However, I got ~2.5 mC/cm^2 using LSDA+U approximation and Berry Phase method:
along x: P = 0.0143864 (mod 0.7250294) C/m^2 along y: P = 0.0143881 (mod 0.7250294) C/m^2 along z: P = 0.0139124 (mod 0.7250294) C/m^2 P_[111]=sqrt(Px*Px + Py*Py + Pz*Pz) = 2.47 mC/cm^2 . The funny part is that using the same structure and ABINIT code I was able to get a value of polarization that is closed to 100 mC/cm^2. I am sure that I did something wrong and there is a simple explanation to this. All other parameters (lattice parameters, wyckoff positions) obtained by PWscf and ABINIT are almost equivalent. Does anybody have any hints? Best regards, -- ===================================== Jess Kondor, PhD student PICYT, Av. Venustiano Carranza 2425-A, San Luis Potos? 78210, M?xico =====================================
