Element: gw

G0W0 calculation setup.

This element allows for specification of the following attributes: coreflag, debug, ibgw, nbgw, nempty, ngridq, reduceq, rmax, rpmat, skipgnd, taskname, vqloff

Attribute: coreflag

Option for treating core. Valid options are:

• all - All electron calculation
• val - Valence electron only calculation
• vab - Core electrons are excluded from the mixed product basis
• xal - All electron treatment of the exchange self-energy only

Attribute: debug

Print debugging information.

Attribute: ibgw

Lower band index for GW output.

Attribute: nbgw

Upper band index for GW output. If not specified, the maximum number of the available states is used.

Attribute: nempty

Number of empty states (cutoff parameter) used in GW. If not specified, the same number as for the groundstate calculations is used.

Attribute: ngridq

k/q-point grid size to be used in GW calculations. If not specified, (2,2,2) k-grid is used.

Attribute: reduceq

Use the crystal symmetry to calculate the dielectric function and perform q-point BZ integration (currently is not implemented).

Attribute: rmax

Determine the basis size for the Fourier-series based interpolation subroutine used for the QP bandstructure plot.

Attribute: rpmat

Skip calculation of the momentum matrix elements but read them from files PMATVV.OUT and PMATCV.OUT.

Attribute: skipgnd

Skip recalculation KS eigenvalues and eigenvectors for the complete k-point grid.

Attribute: taskname

Type of calculations. Available tasks:

• g0w0 - G0W0 calculations
• g0w0_x - Exchange only (Hartree-Fock) G0W0 calculations
• gw0 - Partially self-consistent GW0 calculations
• cohsex - Coulomb-hole and screened-exchange (COHSEX) approximation
• band - QP banstructure as obtained by Fourier interpolation
• dos - QP density of states
• emac - Calculate the macroscopic dielectric function
• vxc - Calculate diagonal matrix elements of the exchange-correlation potential
• pmat - Calculate matrix elements of the momentum operator
• acon - Perform analytic continuation of the correlation self-energy from imaginary to real frequency and calculate QP energies

Attribute: vqloff

The ${\mathbf k/q}$-point offset vector in lattice coordinates.

Element: freqgrid

Frequecy grid parameters.

This element allows for specification of the following attributes: fconv, fgrid, freqmax, nomeg

Attribute: fconv

Frequency convolution type: 'nofreq' - no frequecy dependence of the weights; 'refreq' - weights calculated for real frequecies; 'imfreq' - weights calculated for imaginary frequecies.

Attribute: fgrid

Frequency integration grid type: 'eqdis' - equidistant frequencies from 0 to freqmax; 'gaulag' - Gauss-Laguerre quadrature from 0 to infinity; 'gauleg' - Gauss-Legendre quadrature from 0 to freqmax; 'gaule2' (default) - double Gauss-Legendre quadrature from 0 to freqmax and from freqmax to infinity.

Attribute: freqmax

Parameter of the double frequency grid technique.

Attribute: nomeg

Number of frequency (grid) points.

Element: selfenergy

Options related to the calculations of the correlation self-energy.

This element allows for specification of the following attributes: actype, iopes, nempty, npol, singularity

Attribute: actype

Analytical continuation scheme: 'pade': Pade's approximant (by H. J. Vidberg and J. W. Serence, J. Low Temp. Phys. 29, 179 (1977)) 'mpf': Multi-Pole Fitting (by H. N Rojas, R. W. Godby and R. J. Needs, Phys. Rev. Lett. 74, 1827 (1995))

Attribute: iopes

Solution of the quasiparticle equation: 0 : perturbative G0W0 without energy shift; 1 : perturbative G0W0 with energy shift 2 - iterative G0W0 with energy shift; 3 - iterative G0W0 without energy shift.

Attribute: nempty

Number of empty states to be used to calculate the correlation self energy.

Attribute: npol

Number of poles used in the analytical continuation.

Attribute: singularity

Treatment of the integrable singular terms: 'none': No special treatment (test purpose only); 'mpb' : Auxiliary function method by S. Massidda, M. Posternak, and A. Baldereschi, PRB 48, 5058 (1993); 'crg' : Auxiliary function method by P. Carrier, S. Rohra, and A. Goerling, PRB 75, 205126 (2007).

Element: mixbasis

Mixed basis parameters.

This element allows for specification of the following attributes: epsmb, gmb, lmaxmb

Attribute: epsmb

Attribute: gmb

Attribute: lmaxmb

Element: barecoul

Parameters for the bare coulomb potential: pwm - Maximum G for the pw basis (in gmaxvr*gmb units) stctol - Convergence tolerance of the struct. const. barcevtol - Tolerance to choose basis functions from bare Coulomb matrix eigenvectors.

This element allows for specification of the following attributes: barcevtol, basis, cutofftype, pwm, stctol

Attribute: barcevtol

Attribute: basis

Attribute: cutofftype

Attribute: pwm

Attribute: stctol

Element: scrcoul

Parameters for the dynamically screened Coulomb potential:

This element allows for specification of the following attributes: lmaxdielt, nleblaik, omegap, q0eps, sciavbd, sciavtype, scrtype

Attribute: lmaxdielt

Angular momentum cutoff in anisotropy treatment.

Attribute: nleblaik

Number of Lebedev-Laikov grid points in anisotropy treatment.

Attribute: omegap

Plasmon-pole model fitting parameter (plasmon frequency).

Attribute: q0eps

q0eps - averaging direction q $\to$ 0. Default: (1,1,1)

Attribute: sciavbd

Flag for anisotropic averaging of the dielectric tensor 'body' part.

Attribute: sciavtype

Type of volume averaging: isotropic - Simple averaging along a specified direction using only diagonal components of the dielectric tensor; anisotropic - Anisotropic screening by C. Freysoldt et al., CPC 176, 1-13 (2007).

Attribute: scrtype

Model type: rpa - Full-frequency random-phase approximation; ppm - Godby-Needs plasmon-pole model.

Reused Elements

The following elements can occur more than once in the input file. There for they are listed separately.

Data Types

The Input definition uses derived data types. These are described here.