I am trying to run spin polarized DFT calculation on system Ti2FeSn.
I am doing vc-relax calculation to relax the unit cell but having problem to converge total energy. Total magnetization is also sometimes increases and sometimes decreases on
each iteration step and final total magnetization is also getting converged to '0'. This system is supposed to be half metallic system with magnetic moment of 2 Bohr mag/cell (as per the reference https://doi.org/10.1016/j.intermet.2013.01.005). I am trying to run DFT calculation to see if I can converge to the same results.
I have also attached the pwscf input file which I am using for the calculation in Quantum Espresso:
&CONTROL title = 'Ti2FeSn' , calculation = 'vc-relax' , outdir = '.' , pseudo_dir = '.' , prefix = 'Ti2FeSn' , etot_conv_thr = 1.0D-6 , forc_conv_thr = 1.0D-6 , tstress = .true. , tprnfor = .true. , / &SYSTEM ibrav = 2, celldm(1) = 10, nat = 4, ntyp = 3, ecutwfc = 40 , ecutrho = 400 , occupations = 'smearing' , smearing = 'marzari-vanderbilt' , degauss = 0.01, nspin = 2 , starting_magnetization(1) = 0.2, starting_magnetization(2) = 0.4, starting_magnetization(3) = 0.2, / &ELECTRONS / &IONS / &CELL / ATOMIC_SPECIES Ti 55.84500 ti_pbe_v1.4.uspp.F.UPF Fe 118.71000 Fe.pbe-spn-kjpaw_psl.0.2.1.UPF Sn 47.86700 Sn_pbe_v1.uspp.F.UPF ATOMIC_POSITIONS alat Ti 0.000000000 0.000000000 0.000000000 Ti 0.250000000 0.250000000 0.250000 Fe 0.500000000 0.500000000 0.500000000 Sn -0.250000000 -0.250000000 -0.250000000 K_POINTS automatic 6 6 6 0 0 0
Any suggestion on how can I resolve this issue and get same results as in the reference will be helpful.