GW

Element: gw

G0W0 calculation setup.

contains: freqgrid (optional)
selfenergy (optional)
mixbasis (optional)
barecoul (optional)
scrcoul (optional)
XPath: /input/gw

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
Type: string
Default: "all"
Use: optional
XPath: /input/gw/@coreflag


Attribute: debug

Print debugging information.

Type: boolean
Default: "false"
Use: optional
XPath: /input/gw/@debug


Attribute: ibgw

Lower band index for GW output.

Type: integer
Default: "1"
Use: optional
XPath: /input/gw/@ibgw


Attribute: nbgw

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

Type: integer
Default: "0"
Use: optional
XPath: /input/gw/@nbgw


Attribute: nempty

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

Type: integer
Default: "0"
Use: optional
XPath: /input/gw/@nempty


Attribute: ngridq

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

Type: integertriple
Default: "0 0 0"
Use: optional
XPath: /input/gw/@ngridq


Attribute: reduceq

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

Type: boolean
Default: "false"
Use: optional
XPath: /input/gw/@reduceq


Attribute: rmax

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

Type: fortrandouble
Default: "40.0"
Use: optional
XPath: /input/gw/@rmax


Attribute: rpmat

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

Type: boolean
Default: "false"
Use: optional
XPath: /input/gw/@rpmat


Attribute: skipgnd

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

Type: boolean
Default: "false"
Use: optional
XPath: /input/gw/@skipgnd


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
Type: string
Default: "g0w0"
Use: optional
XPath: /input/gw/@taskname


Attribute: vqloff

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

Type: vect3d
Default: "0.0d0 0.0d0 0.0d0"
Use: optional
XPath: /input/gw/@vqloff

Element: freqgrid

Frequecy grid parameters.

Type: no content
XPath: /input/gw/freqgrid

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.

Type: string
Default: "imfreq"
Use: optional
XPath: /input/gw/freqgrid/@fconv


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.

Type: string
Default: "gaule2"
Use: optional
XPath: /input/gw/freqgrid/@fgrid


Attribute: freqmax

Parameter of the double frequency grid technique.

Type: fortrandouble
Default: "1.0d0"
Use: optional
XPath: /input/gw/freqgrid/@freqmax


Attribute: nomeg

Number of frequency (grid) points.

Type: integer
Default: "16"
Use: optional
XPath: /input/gw/freqgrid/@nomeg

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))

Type: string
Default: "pade"
Use: optional
XPath: /input/gw/selfenergy/@actype


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.

Type: integer
Default: "0"
Use: optional
XPath: /input/gw/selfenergy/@iopes


Attribute: nempty

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

Type: integer
Default: "0"
Use: optional
XPath: /input/gw/selfenergy/@nempty


Attribute: npol

Number of poles used in the analytical continuation.

Type: integer
Default: "0"
Use: optional
XPath: /input/gw/selfenergy/@npol


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).

Type: string
Default: "mpb"
Use: optional
XPath: /input/gw/selfenergy/@singularity

Element: mixbasis

Mixed basis parameters.

Type: no content
XPath: /input/gw/mixbasis

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

Attribute: epsmb

Type: fortrandouble
Default: "1.0d-4"
Use: optional
XPath: /input/gw/mixbasis/@epsmb


Attribute: gmb

Type: fortrandouble
Default: "1.0"
Use: optional
XPath: /input/gw/mixbasis/@gmb


Attribute: lmaxmb

Type: integer
Default: "3"
Use: optional
XPath: /input/gw/mixbasis/@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.

Type: no content
XPath: /input/gw/barecoul

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

Attribute: barcevtol

Type: fortrandouble
Default: "0.1d0"
Use: optional
XPath: /input/gw/barecoul/@barcevtol


Attribute: basis

Type: string
Default: "mb"
Use: optional
XPath: /input/gw/barecoul/@basis


Attribute: cutofftype

Type: string
Default: "none"
Use: optional
XPath: /input/gw/barecoul/@cutofftype


Attribute: pwm

Type: fortrandouble
Default: "2.0d0"
Use: optional
XPath: /input/gw/barecoul/@pwm


Attribute: stctol

Type: fortrandouble
Default: "1.0d-15"
Use: optional
XPath: /input/gw/barecoul/@stctol

Element: scrcoul

Parameters for the dynamically screened Coulomb potential:

Type: no content
XPath: /input/gw/scrcoul

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

Attribute: lmaxdielt

Angular momentum cutoff in anisotropy treatment.

Type: integer
Default: "2"
Use: optional
XPath: /input/gw/scrcoul/@lmaxdielt


Attribute: nleblaik

Number of Lebedev-Laikov grid points in anisotropy treatment.

Type: integer
Default: "5810"
Use: optional
XPath: /input/gw/scrcoul/@nleblaik


Attribute: omegap

Plasmon-pole model fitting parameter (plasmon frequency).

Type: fortrandouble
Default: "1.0d0"
Use: optional
XPath: /input/gw/scrcoul/@omegap


Attribute: q0eps

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

Type: vect3d
Default: "1.0d0 1.0d0 1.0d0"
Use: optional
XPath: /input/gw/scrcoul/@q0eps


Attribute: sciavbd

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

Type: boolean
Default: "false"
Use: optional
XPath: /input/gw/scrcoul/@sciavbd


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).

Type: string
Default: "isotropic"
Use: optional
XPath: /input/gw/scrcoul/@sciavtype


Attribute: scrtype

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

Type: string
Default: "rpa"
Use: optional
XPath: /input/gw/scrcoul/@scrtype

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.

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