I am performing a spin polarized DFT calculations in Quantum Espresso on a Co2MnSi ferromagnetic crystal. For this I have performed these steps:
vc-relax calculation to find its lattice constant. Here is some lines from output file:
CELL_PARAMETERS (alat= 10.00000000) -0.531670336 0.000000000 0.531670336 0.000000000 0.531670336 0.531670336 -0.531670336 0.531670336 -0.000000000 ATOMIC_POSITIONS (alat) Co 0.000000000 0.000000000 -0.000000000 Mn 0.265835168 0.265835168 0.265835168 Co 0.531670336 0.531670336 0.531670336 Si -0.265835168 -0.265835168 -0.265835168 End final coordinates
Lattice constant found is as,
a = (10/0.5)*0.531670336 = 10.63340672 Bohr and the final 'total magnetization' found at the end of the calculation is as follows:
total magnetization = 5.00 Bohr mag/cell absolute magnetization = 5.39 Bohr mag/cell/cell
2) Now I have plugged the value of lattice constant, (
scf input file and performed the 'scf' calculation. But in the output file of
total magnetization is different than the
total magnetization = 4.56 Bohr mag/cell absolute magnetization = 5.01 Bohr mag/cell
Correct 'total magnetization' for this system is exact 5.00 (which I have got in the
vc-relax calculation) but why I'm getting different
total magnetization from the
Shouldn't it be same cause this will affect the DOS calculation also? Also the total energy from two different calculation is different. Why is so? Am I performing the steps wrongly?
Please clarify it.
You can find the input and output files here