Advanced Tricks for Breaking Symmetry
Posted: Tue Mar 07, 2017 6:59 am
I am trying to reproduce some prior results (albeit, calculated using a different ab-initio method) for a 2-primitive-cell supercell (8 atoms) of AFM(L11) Ru2MnSn showing:
1. Half-metallic behavior (a gap at the fermi level in one spin channel)
2. Asymmetry in the DOS for the two Mn atoms
While I can get an AFM solution (one Mn up, one Mn down, reasonable magnetic moments on each compared to experiment), I cannot for the life of me to get the DOS of Mn_up to look different from the spin-inverted DOS of Mn_dn, that is, my DOS plot is symmetric around the x-axis. The fact that I can get an AFM solution at all makes me think I've missed something more subtle.
I've tried:
1. ISYM = 2, 1, 0
2. Different MAGMOMs on the two Mn sites (MAGMOM = 6 -5 1 -1 -1 1 1 -1)
3. Breaking up the POSCAR to specify each site as a separate species (Mn Mn Ru Ru Ru Ru Sn Sn \n 1 1 1 1 1 1 1 1) and having multiple copies of each species' POTCAR in the input POTCAR
Am I missing anything else?
1. Half-metallic behavior (a gap at the fermi level in one spin channel)
2. Asymmetry in the DOS for the two Mn atoms
While I can get an AFM solution (one Mn up, one Mn down, reasonable magnetic moments on each compared to experiment), I cannot for the life of me to get the DOS of Mn_up to look different from the spin-inverted DOS of Mn_dn, that is, my DOS plot is symmetric around the x-axis. The fact that I can get an AFM solution at all makes me think I've missed something more subtle.
I've tried:
1. ISYM = 2, 1, 0
2. Different MAGMOMs on the two Mn sites (MAGMOM = 6 -5 1 -1 -1 1 1 -1)
3. Breaking up the POSCAR to specify each site as a separate species (Mn Mn Ru Ru Ru Ru Sn Sn \n 1 1 1 1 1 1 1 1) and having multiple copies of each species' POTCAR in the input POTCAR
Am I missing anything else?