# QS

parameters needed to set up the Quickstep framework [Edit on GitHub]

Subsections

- CDFT
- DDAPC_RESTRAINT
- DFTB
- DISTRIBUTION
- LRIGPW
- MULLIKEN_RESTRAINT
- OPTIMIZE_LRI_BASIS
- OPT_DMFET
- OPT_EMBED
- S2_RESTRAINT
- SE
- XTB

## Keywords

- ALMO_SCF

- ALPHA0_HARD

- CLUSTER_EMBED_SUBSYS

- CORE_PPL

- DFET_EMBEDDED

- DMFET_EMBEDDED

- EMBED_CUBE_FILE_NAME

- EMBED_RESTART_FILE_NAME

- EMBED_SPIN_CUBE_FILE_NAME

- EPSFIT

- EPSISO

- EPSRHO0

- EPSSVD

- EPS_CORE_CHARGE

- EPS_CPC

- EPS_DEFAULT

- EPS_FILTER_MATRIX

- EPS_GVG_RSPACE

- EPS_KG_ORB

- EPS_PGF_ORB

- EPS_PPL

- EPS_PPNL

- EPS_RHO

- EPS_RHO_GSPACE

- EPS_RHO_RSPACE

- EXTRAPOLATION

- EXTRAPOLATION_ORDER

- FORCE_PAW

- GAPW_1C_BASIS

- HIGH_LEVEL_EMBED_SUBSYS

- KG_METHOD

- LADDN0

- LMAXN0

- LMAXN1

- LS_SCF

- MAX_RAD_LOCAL

- METHOD

- MIN_PAIR_LIST_RADIUS

- PW_GRID

- PW_GRID_BLOCKED

- PW_GRID_LAYOUT

- QUADRATURE

- REF_EMBED_SUBSYS

- STO_NG

- TRANSPORT

## Keyword descriptions

ALMO_SCF: logical = F

  Lone keyword: `T`

  Usage: ALMO_SCF

  Perform ALMO SCF [Edit on GitHub]

ALPHA0_HARD: real = 0.00000000E+000

  Aliases: ALPHA0_H ,ALPHA0

  Usage: ALPHA0_HARD real

  GAPW: Exponent for hard compensation charge [Edit on GitHub]

CLUSTER_EMBED_SUBSYS: logical = F

  Lone keyword: `T`

  Usage: CLUSTER_EMBED_SUBSYS FALSE

  A cluster treated with DFT in DFT embedding. [Edit on GitHub]

CORE_PPL: enum = ANALYTIC

  Usage: CORE_PPL ANALYTIC

  Valid values:

  - `ANALYTIC` Analytic integration of integrals

  - `GRID` Numerical integration on real space grid. Lumped together with core charge

  Specifies the method used to calculate the local pseudopotential contribution. [Edit on GitHub]

DFET_EMBEDDED: logical = F

  Lone keyword: `T`

  Usage: DFET_EMBEDDED FALSE

  Calculation with DFT-embedding potential. [Edit on GitHub]

DMFET_EMBEDDED: logical = F

  Lone keyword: `T`

  Usage: DMFET_EMBEDDED FALSE

  Calculation with DM embedding potential. [Edit on GitHub]

EMBED_CUBE_FILE_NAME: string

  Usage: EMBED_CUBE_FILE_NAME <FILENAME>

  Root of the file name where to read the embedding potential (guess) as a cube. [Edit on GitHub]

EMBED_RESTART_FILE_NAME: string

  Usage: EMBED_RESTART_FILE_NAME <FILENAME>

  Root of the file name where to read the embedding potential guess. [Edit on GitHub]

EMBED_SPIN_CUBE_FILE_NAME: string

  Usage: EMBED_SPIN_CUBE_FILE_NAME <FILENAME>

  Root of the file name where to read the spin part of the embedding potential (guess) as a cube. [Edit on GitHub]

EPSFIT: real = 1.00000000E-004

  Aliases: EPS_FIT

  Usage: EPSFIT real

  GAPW: precision to give the extension of a hard gaussian [Edit on GitHub]

EPSISO: real = 1.00000000E-012

  Aliases: EPS_ISO

  Usage: EPSISO real

  GAPW: precision to determine an isolated projector [Edit on GitHub]

EPSRHO0: real = 1.00000000E-006

  Aliases: EPSVRHO0 ,EPS_VRHO0

  Usage: EPSRHO0 real

  GAPW : precision to determine the range of V(rho0-rho0soft) [Edit on GitHub]

EPSSVD: real = 1.00000000E-008

  Aliases: EPS_SVD

  Usage: EPS_SVD real

  GAPW: tolerance used in the singular value decomposition of the projector matrix [Edit on GitHub]

EPS_CORE_CHARGE: real

  Usage: EPS_CORE_CHARGE real

  Precision for mapping the core charges.Overrides EPS_DEFAULT/100.0 value [Edit on GitHub]

EPS_CPC: real

  Usage: EPS_CPC real

  Sets precision of the GAPW projection. Overrides EPS_DEFAULT value [Edit on GitHub]

EPS_DEFAULT: real = 1.00000000E-010

  Usage: EPS_DEFAULT real

  Mentions: ⭐Molecular Dynamics

  Try setting all EPS_xxx to values leading to an energy correct up to EPS_DEFAULT [Edit on GitHub]

EPS_FILTER_MATRIX: real = 0.00000000E+000

  Usage: EPS_FILTER_MATRIX 1.0E-6

  Sets the threshold for filtering matrix elements. [Edit on GitHub]

EPS_GVG_RSPACE: real

  Aliases: EPS_GVG

  Usage: EPS_GVG_RSPACE real

  Sets precision of the realspace KS matrix element integration. Overrides SQRT(EPS_DEFAULT) value [Edit on GitHub]

EPS_KG_ORB: real

  Usage: EPS_KG_ORB 1.0E-8

  Sets precision used in coloring the subsets for the Kim-Gordon method. Overrides SQRT(EPS_DEFAULT) value [Edit on GitHub]

EPS_PGF_ORB: real

  Usage: EPS_PGF_ORB real

  Sets precision of the overlap matrix elements. Overrides SQRT(EPS_DEFAULT) value [Edit on GitHub]

EPS_PPL: real = 1.00000000E-002

  Usage: EPS_PPL real

  Adjusts the precision for the local part of the pseudo potential. [Edit on GitHub]

EPS_PPNL: real

  Usage: EPS_PPNL real

  Sets precision of the non-local part of the pseudo potential. Overrides sqrt(EPS_DEFAULT) value [Edit on GitHub]

EPS_RHO: real

  Usage: EPS_RHO real

  Sets precision of the density mapping on the grids.Overrides EPS_DEFAULT value [Edit on GitHub]

EPS_RHO_GSPACE: real

  Usage: EPS_RHO_GSPACE real

  Sets precision of the density mapping in gspace.Overrides EPS_DEFAULT value. Overrides EPS_RHO value [Edit on GitHub]

EPS_RHO_RSPACE: real

  Usage: EPS_RHO_RSPACE real

  Sets precision of the density mapping in rspace.Overrides EPS_DEFAULT value. Overrides EPS_RHO value [Edit on GitHub]

EXTRAPOLATION: enum = ASPC

  Aliases: INTERPOLATION ,WF_INTERPOLATION

  Usage: EXTRAPOLATION PS

  Valid values:

  - `USE_GUESS` Use the method specified with SCF_GUESS, i.e. no extrapolation

  - `USE_PREV_P` Use the previous density matrix

  - `USE_PREV_RHO_R` Use the previous density in real space

  - `LINEAR_WF` Linear extrapolation of the wavefunction (not available for K-points)

  - `LINEAR_P` Linear extrapolation of the density matrix

  - `LINEAR_PS` Linear extrapolation of the density matrix times the overlap matrix (not available for K-points)

  - `USE_PREV_WF` Use the previous wavefunction (not available for K-points)

  - `PS` Higher order extrapolation of the density matrix times the overlap matrix (not available for K-points)

  - `FROZEN` Frozen …

  - `ASPC` Always stable predictor corrector, similar to PS, but going for MD stability instead of initial guess accuracy. (not available for K-points)

  References: Kolafa2004, VandeVondele2005, Khne2007

  Mentions: ⭐Molecular Dynamics

  Extrapolation strategy for the wavefunction during e.g. MD. Not all options are available for all simulation methods. PS and ASPC are recommended, see also EXTRAPOLATION_ORDER. [Edit on GitHub]

EXTRAPOLATION_ORDER: integer = 3

  Usage: EXTRAPOLATION_ORDER {integer}

  Mentions: ⭐Molecular Dynamics

  Order for the PS or ASPC extrapolation (typically 2-4). Higher order might bring more accuracy, but comes, for large systems, also at some cost. In some cases, a high order extrapolation is not stable, and the order needs to be reduced. [Edit on GitHub]

FORCE_PAW: logical = F

  Lone keyword: `T`

  Usage: FORCE_PAW

  Use the GAPW scheme also for atoms with soft basis sets, i.e. the local densities are computed even if hard and soft should be equal. If this keyword is not set to true, those atoms with soft basis sets are treated by a GPW scheme, i.e. the corresponding density contribution goes on the global grid and is expanded in PW. This option nullifies the effect of the GPW_TYPE in the atomic KIND [Edit on GitHub]

GAPW_1C_BASIS: enum = ORB

  Usage: GAPW_1C_BASIS MEDIUM

  Valid values:

  - `ORB` Use orbital basis set.

  - `EXT_SMALL` Extension using Small number of primitive Gaussians.

  - `EXT_MEDIUM` Extension using Medium number of primitive Gaussians.

  - `EXT_LARGE` Extension using Large number of primitive Gaussians.

  - `EXT_VERY_LARGE` Extension using Very Large number of primitive Gaussians.

  Specifies how to construct the GAPW one center basis set. Default is to use the primitives from the orbital basis. [Edit on GitHub]

HIGH_LEVEL_EMBED_SUBSYS: logical = F

  Lone keyword: `T`

  Usage: HIGH_LEVEL_EMBED_SUBSYS FALSE

  A cluster treated with a high-level method in DFT embedding. [Edit on GitHub]

KG_METHOD: logical = F

  Lone keyword: `T`

  Usage: KG_METHOD

  References: Iannuzzi2006, Brelaz1979, Andermatt2016

  Use a Kim-Gordon-like scheme. [Edit on GitHub]

LADDN0: integer = 99

  Usage: LADDN0 integer

  GAPW : integer added to the max L of the basis set, used to determine the maximum value of L for the compensation charge density. [Edit on GitHub]

LMAXN0: integer = 2

  Aliases: LMAXRHO0

  Usage: LMAXN0 integer

  GAPW : max L number for the expansion compensation densities in spherical gaussians [Edit on GitHub]

LMAXN1: integer = -1

  Aliases: LMAXRHO1

  Usage: LMAXN1 integer

  GAPW : max L number for expansion of the atomic densities in spherical gaussians [Edit on GitHub]

LS_SCF: logical = F

  Lone keyword: `T`

  Usage: LS_SCF

  Perform a linear scaling SCF [Edit on GitHub]

MAX_RAD_LOCAL: real = 2.50000000E+001

  Usage: MAX_RAD_LOCAL real

  GAPW : maximum radius of gaussian functions included in the generation of projectors [Edit on GitHub]

METHOD: enum = GPW

  Usage: METHOD GAPW

  Valid values:

  - `GAPW` Gaussian and augmented plane waves method

  - `GAPW_XC` Gaussian and augmented plane waves method only for XC

  - `GPW` Gaussian and plane waves method

  - `LRIGPW` Local resolution of identity method

  - `RIGPW` Resolution of identity method for HXC terms

  - `MNDO` MNDO semiempirical

  - `MNDOD` MNDO-d semiempirical

  - `AM1` AM1 semiempirical

  - `PM3` PM3 semiempirical

  - `PM6` PM6 semiempirical

  - `PM6-FM` PM6-FM semiempirical

  - `PDG` PDG semiempirical

  - `RM1` RM1 semiempirical

  - `PNNL` PNNL semiempirical

  - `DFTB` DFTB Density Functional based Tight-Binding

  - `XTB` GFN-xTB Extended Tight-Binding

  - `OFGPW` OFGPW Orbital-free GPW method

  References: Lippert1997, Lippert1999, Krack2000, VandeVondele2005, VandeVondele2006, Dewar1977, Dewar1985, Rocha2006, Stewart1989, Thiel1992, Repasky2002, Stewart2007, VanVoorhis2015, Chang2008

  Mentions: ⭐X-Ray Absorption from TDDFT

  Specifies the electronic structure method that should be employed [Edit on GitHub]

MIN_PAIR_LIST_RADIUS: real = 0.00000000E+000

  Usage: MIN_PAIR_LIST_RADIUS real

  Set the minimum value [Bohr] for the overlap pair list radius. Default is 0.0 Bohr, negative values are changed to the cell size. This allows to control the sparsity of the KS matrix for HFX calculations. [Edit on GitHub]

PW_GRID: enum = NS-FULLSPACE

  Usage: PW_GRID NS-FULLSPACE

  Valid values:

  - `SPHERICAL`

    - not tested

  - `NS-FULLSPACE` tested

  - `NS-HALFSPACE`

    - not tested

  What kind of PW_GRID should be employed [Edit on GitHub]

PW_GRID_BLOCKED: enum = FREE

  Usage: PW_GRID_BLOCKED FREE

  Valid values:

  - `FREE` CP2K will select an appropriate value

  - `TRUE` blocked

  - `FALSE` not blocked

  Can be used to set the distribution in g-space for the pw grids and their FFT. [Edit on GitHub]

PW_GRID_LAYOUT: integer[2] = -1 -1

  Usage: PW_GRID_LAYOUT 4 16

  Force a particular real-space layout for the plane waves grids. Numbers ≤ 0 mean that this dimension is free, incorrect layouts will be ignored. The default (/-1,-1/) causes CP2K to select a good value, i.e. plane distributed for large grids, more general distribution for small grids. [Edit on GitHub]

QUADRATURE: enum = GC_LOG

  Usage: QUADRATURE GC_SIMPLE

  Valid values:

  - `GC_SIMPLE` Gauss-Chebyshev quadrature

  - `GC_TRANSFORMED` Transformed Gauss-Chebyshev quadrature

  - `GC_LOG` Logarithmic transformed Gauss-Chebyshev quadrature

  GAPW: algorithm to construct the atomic radial grids [Edit on GitHub]

REF_EMBED_SUBSYS: logical = F

  Lone keyword: `T`

  Usage: REF_EMBED_SUBSYS FALSE

  A total, reference, system in DFT embedding. [Edit on GitHub]

STO_NG: integer = 6

  Usage: STO_NG

  Order of Gaussian type expansion of Slater orbital basis sets. [Edit on GitHub]

TRANSPORT: logical = F

  Lone keyword: `T`

  Usage: TRANSPORT

  Perform transport calculations (coupling CP2K and OMEN) [Edit on GitHub]