5.20.2. scf.SCF

class eminus.scf.SCF(atoms, xc='lda,vwn', pot='gth', guess='random', etol=1e-7, gradtol=None, sic=False, disp=False, opt=None, verbose=None)

Perform direct minimizations.

Parameters:

atoms – Atoms object.

Keyword Arguments:

• xc –

  Comma-separated exchange-correlation functional description.

  Adding “libxc:” before a functional will use the Libxc interface for that functional, e.g., with libxc:mgga_x_scan,libxc:mgga_c_scan.

• pot –

  Type of potential.

  Can be one of “GTH” (default), “Coulomb”, “Harmonic”, or “Ge”. Alternatively, a path to a directory containing custom GTH pseudopotential files can be given.

• guess –

  Initial guess for the wave functions.

  Can be one of “random” (default) or “pseudo”. Adding “symm” to the string will use the same coefficients for both spin channels, e.g., symm-rand.

• etol – Convergence tolerance of the total energy.

• gradtol –

  Convergence tolerance of the gradient norm.

  This tolerance will only be used in conjugate gradient methods.

• sic – Calculate the Kohn-Sham Perdew-Zunger SIC energy at the end of the SCF.

• disp –

  Calculate a dispersion correction.

  A dictionary can be used to pass arguments to the respective function, e.g., with {"version": "d3zero", "atm": False, "xc": "scan"}.

• opt –

  Dictionary to customize the minimization methods.

  The keys can be chosen out of “sd”, “lm”, “pclm”, “cg”, “pccg”, and “auto”. Defaults to {"auto": 250}.

• verbose –

  Level of output.

  Can be one of “critical”, “error”, “warning”, “info” (default), or “debug”. An integer value can be used as well, where larger numbers mean more output, starting from 0. Defaults to the verbosity level of the Atoms object.

Methods

clear()	Initialize or clear intermediate results.
converge_bands(**kwargs)	Converge occupied bands after an SCF calculation.
converge_empty_bands([Nempty])	Converge unoccupied bands after converging occ.
kernel(**kwargs)	Run the self-consistent field (SCF) calculation.
recenter([center])	Recenter the system inside the cell.
run(**kwargs)	Run the self-consistent field (SCF) calculation.
view(*args, **kwargs)	Unified display function.
write(filename, *args, **kwargs)	Unified file writer function.

Attributes

atoms	Atoms object.
guess	Initial wave functions guess.
kpts	Pass-through to the KPoints object of the Atoms object.
opt	Minimization methods.
pot	Used potential.
psp	Pseudopotential path.
symmetric	Determines if the initial guess is the same for both spin channels.
verbose	Verbosity level.
xc	Exchange-correlation functional.
xc_params	Exchange-correlation functional parameters.
xc_params_defaults	Get the default exchange-correlation functional parameters.
xc_type	Determines the exchange-correlation family.
etol	Total energy convergence tolerance.
gradtol	Gradient norm convergence tolerance.
sic	Enables the SIC energy calculation.
disp	Enables the dispersion correction calculation.
smear_update	Steps after the smeared occupations are recalculated.
energies	Energy object holding energy contributions.
is_converged	Determines the SCF object convergence.
W	Unconstrained wave functions.

clear()

Initialize or clear intermediate results.

converge_bands(**kwargs)

Converge occupied bands after an SCF calculation.

Keyword Arguments:

**kwargs – Pass-through keyword arguments.

converge_empty_bands(Nempty=None, **kwargs)

Converge unoccupied bands after converging occ. bands.

Keyword Arguments:

• Nempty – Number of empty states.

• **kwargs – Pass-through keyword arguments.

kernel(**kwargs)

Run the self-consistent field (SCF) calculation.

Keyword Arguments:

**kwargs – Pass-through keyword arguments.

Returns:

Total energy.

recenter(center=None)

Recenter the system inside the cell.

Keyword Arguments:

center – Point to center the system around.

run(**kwargs)

Run the self-consistent field (SCF) calculation.

Keyword Arguments:

**kwargs – Pass-through keyword arguments.

Returns:

Total energy.

W

Unconstrained wave functions.

property atoms

Atoms object.

disp

Enables the dispersion correction calculation.

energies

Energy object holding energy contributions.

etol

Total energy convergence tolerance.

gradtol

Gradient norm convergence tolerance.

property guess

Initial wave functions guess.

is_converged

Determines the SCF object convergence.

property kpts

Pass-through to the KPoints object of the Atoms object.

property opt

Minimization methods.

property pot

Used potential.

property psp

Pseudopotential path.

sic

Enables the SIC energy calculation.

smear_update

Steps after the smeared occupations are recalculated.

property symmetric

Determines if the initial guess is the same for both spin channels.

property verbose

Verbosity level.

property xc

Exchange-correlation functional.

property xc_params

Exchange-correlation functional parameters.

property xc_params_defaults

Get the default exchange-correlation functional parameters.

property xc_type

Determines the exchange-correlation family.