Dear doaa haleem : in your “111” case, your unit cell is twice longer in the X direction than in other two(did you have a look at the structure figure??) In other two cases, the lattice vectors are more cubic, yet you have Hf in the “A” positionand Ba in the “B” position (in the oxygen octahedron) of the perovskite. Is this as supposed to be?Won’t this be the other way around? Concerning the spin different from 0, this might be due to settings in your LDAU block.You switch some U on Hf and set SpinPolarized =T; what do you expect, in fact? In order to better see what’s going on you can add some printout (Mulliken charges…).I’d say, try first to get a reasonable structure in non-magnetic case without LDA+U... Best regards Andrei Postnikov ----- doaa haleem <[email protected]> a écrit : >I am writing this mail to discuss a problem I have faced when I was >calculating using siesta package, I am using siesta 4.0 , I am working on >some peroveskite structure , at the beginning I have used calculations using >GGA only ,it is expected that the final structure (XSF) to be the same as the >start structure (FCC) ,but it isn't and it consists only from 5 atoms with >wrong positions..(I will attach the fdf file, XSF, and gnuplot draw that >resulted for the previous case named after "case 1") The same have happened >when using GGA+U (case 2)Trying to solve this problem I have used the geometry >constraint to fix Hf atom and all 3-O atoms as in the perovskite BaHfO3, the >resulted structure is wright but -in the DOS and PDOS - the spin up DOS isn't >the same as the spin down DOS ( I will send the fdf file , XSF and gnuplot >draw for the previous case named after "case ") I tried also to use "variable >cell command , repeating the run and changing the k-grid and mesh cut off but >the problem is still existing .It is notable that I am using the pseudo >potentials uploaded on siesta web page So, please help me to solve this >problem .I need the the structure to be right, the spin up the same as the >spin down and the total spin is zero .Thank you
