Spin Configuration

Spin polarization is controlled by the "ispin" tag in calc_config.json.

To include spin polarization, set "ispin": "auto" in calc_config.json; otherwise set "ispin": 1. With this setting, all elements with valence d or f electrons will start with initial magnetic moments of 5 and 7 \(\mu_B\), respectively.

See more about ISPIN in VASP: ISPIN.

The elements considered to be \(d\) and \(f\) block can be found in d_f_block.json.

d- and f-block elements

d_f_block.json

{
  "d_block": [
    "Sc",
    "Ti",
    "V",
    "Cr",
    "Mn",
    "Fe",
    "Co",
    "Ni",
    "Cu",
    "Zn",
    "Y",
    "Zr",
    "Nb",
    "Mo",
    "Tc",
    "Ru",
    "Rh",
    "Pd",
    "Ag",
    "Cd",
    "Lu",
    "Hf",
    "Ta",
    "W",
    "Re",
    "Os",
    "Ir",
    "Pt",
    "Au",
    "Hg"
  ],
  "f_block": [
    "La",
    "Ce",
    "Pr",
    "Nd",
    "Pm",
    "Sm",
    "Eu",
    "Gd",
    "Tb",
    "Dy",
    "Ho",
    "Er",
    "Tm",
    "Yb",
    "Ac",
    "Th",
    "Pa",
    "U",
    "Np",
    "Pu"
  ]
}

VaspManager also accepts an additional argument magmom_per_atom_cutoff which defaults to 0.0, although I often use a value around 0.1 to avoid numerical noise and only use spin polarization in further calculations if they really need it. If this argument is passed, rlx calculations that finish with a magmom per atom less than this value with be re-run without spin polarization. This argument only affects rlx calculations, and the spin setting for following static, bulkmod, or elastic calculations is inferred from the final rlx calculation.