SMEAR

Define the smearing of the MO occupation numbers [Edit on GitHub]

Keywords

Keyword descriptions

SECTION_PARAMETERS: logical = F

Lone keyword: T

Usage: &SMEAR ON

Controls the activation of smearing [Edit on GitHub]

ELECTRONIC_TEMPERATURE: real = 3.00000000E+002 [K]

Aliases: ELEC_TEMP ,TELEC

Usage: ELECTRONIC_TEMPERATURE [K] 300

Electronic temperature in the case of Fermi-Dirac smearing [Edit on GitHub]

EPS_FERMI_DIRAC: real = 1.00000000E-010

Usage: EPS_FERMI_DIRAC 1.0E-6

Accuracy checks on occupation numbers use this as a tolerance [Edit on GitHub]

FIXED_MAGNETIC_MOMENT: real = -1.00000000E+002

Usage: FIXED_MAGNETIC_MOMENT 1.5

Imposed difference between the numbers of electrons of spin up and spin down: m = n(up) - n(down). A negative value (default) allows for a change of the magnetic moment. -1 specifically keeps an integer number of spin up and spin down electrons. [Edit on GitHub]

LIST: real[ ]

Usage: LIST 2.0 0.6666 0.6666 0.66666 0.0 0.0

A list of fractional occupations to use. Must match the number of states and sum up to the correct number of electrons [Edit on GitHub]

METHOD: enum = GAUSSIAN

Usage: METHOD Fermi_Dirac

Valid values:

  • FERMI_DIRAC Fermi-Dirac distribution defined by the keyword ELECTRONIC_TEMPERATURE. Use this method if the temperature equivalence is important for you, e.g. if you want to compute some properties based on the occupations. If you use this method without interest in electronic temperature, it’s suggested to use extrapolated result from finite ELECTRONIC_TEMPERATURE to ELECTRONIC_TEMPERATURE = 0. Note the forces and stress are consistent with the free energy and not with the extrapolated energy.

  • ENERGY_WINDOW Energy window defined by the keyword WINDOW_SIZE.

  • LIST Use a fixed list of occupations.

  • GAUSSIAN Gaussian broadening with width SIGMA; should work well in most cases. With this method you have to use extrapolated results from finite SIGMA results to SIGMA = 0, but usually this value would not be quite accurate without systematically reducing SIGMA. Note the forces and stress are consistent with the free energy and not with the extrapolated energy.

  • METHFESSEL_PAXTON First-order Methfessel-Paxton distribution with width SIGMA. Don’t use it for semiconductors and insulators because the partial occupancies can be unphysical and thus lead to wrong results.

  • MARZARI_VANDERBILT Marzari-Vanderbilt cold smearing with width SIGMA.

Smearing method to be applied [Edit on GitHub]

SIGMA: real = 2.00000000E-003 [hartree]

Usage: SIGMA [eV] 0.2

Smearing width sigma (in energy units) in the case of Gaussian, Methfessel-Paxton or Marzari-Vanderbilt smearing. [Edit on GitHub]

WINDOW_SIZE: real = 0.00000000E+000 [hartree]

Usage: WINDOW_SIZE [eV] 0.3

Size of the energy window centred at the Fermi level [Edit on GitHub]