jxc
Full name: ase2sprkkr.input_parameters.definitions.jxc
Description
DOS task input parameters definition
Description of the sections and parameters
Input parameters for task jxc
INPUT PARAMETERS jxc contains:
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SECTION CONTROL contains:
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DATASET : String The custom field for the description of the problem - the output files will have called 'DATASET.<ext>'.
ADSI : FixedValue(JXC) ≝ JXC Type of the computation.
POTFIL : String The potential file (see SPRKKR documentation for its format). It isn't necessary to set it, it will be set by the calculator.
KRWS : Integer ≝ 1 (optional) If it is 0, RWS is taken from the potential file and scaled. If 1, RWS is calculated by scaling the muffin-tin radii by a common scaling factor. (This setting is forced in the case of FULLPOT.)
KRMT : AnyOf(0,1,2,3,4,5,6) (optional)
Possible values:
0 RMT is taken from the potential file
1 RMT = min( x*RWS )
2 RMT = min( d_ij / 2 )
3 RMT from atomic charge density (=> KRWS=1)
4 RMT from atomic Hartree potential (=> KRWS=1)
5 RMT from total atomic potential (=> KRWS=1)
6 take average of 3 and 4 (=> KRWS=1)
It controls how the muffin-tin radii are calculated.
PRINT : Integer ≝ 0 (optional) Verbosity of the output (0-5). Do not affect the results in any way, just the amount of the printed output.
NONMAG : Flag ≝ False Set this flag, if it is known that the system considered is non-magnetic. This leads to a higher symmetry and a faster calculation.
SECTION TAU contains:
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BZINT : AnyOf(POINTS,WEYL) ≝ POINTS
Possible values:
POINTS special points method
WEYL Weyl method
The Weyl method (BZINT=WEYL) is a point sampling method using more or less ran-
dom points. The number of k-points used for the integration varies quadratically be-
tween 0.0 and ImE according to the imaginary part of the energy.
The special point method (BZINT=POINTS) uses a regular k-point grid with NKTAB
points. It is the standard method and gives a good compromise concerning accuracy
and efficiency. For BZINT=POINTS the parameter NKTAB will be adjusted to allow a
regular mesh.
The mode of BZ-integration used for calculation of the scattering path operator τ
NKTAB : Integer ≝ 250 (optional) Number of points for the special points method
NKTAB2D : Integer (optional) Number of points for the special points method for 2D region of 2D problem
NKTAB3D : Integer (optional) Number of points for the special points method for 3D region of 2D problem
NKMIN : Integer ≝ 300 Minimal number of k-points used for Weyl integration
NKMAX : Integer ≝ 500 Maximal number of k-points used for Weyl integration
Expert options:
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CLUSTER : Flag ≝ False (optional, expert) Do cluster type calculation.
NSHLCLU : Integer (optional, expert) Number of atomic shells around the central atom of a cluster
CLURAD : Integer (optional, expert) Radius of the cluster in multiples of ALAT.
IQCNTR : Site (optional, expert) The center of the cluster is set at the site position with number IQCNTR of the specified basis.
ITCNTR : AtomicType (optional, expert) The center of the cluster is set at one of the site positions that is occupied by the atomic type ITCNTR.
NLOUT : Integer ≝ 3 (optional, expert) The calculated τ -matrix is printed up to lmax=NLOUT.
MOL : Flag ≝ False (optional, expert) Cluster type calculation but for a molecular system. The system is specified as for CLUSTER.
SECTION ENERGY contains:
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GRID : Array(of Integer) ≝ [5]
NE : Array(of Integer) ≝ [32] Number of points in energy-mesh
ImE : Energy (<Real> [Ry|eV]) ≝ 0.0 (optional)
EMIN : Real ≝ -0.2 The real part of the lowest E-value
SECTION SCF contains:
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NITER : Integer ≝ 200 Maximal number of iterations of the SCF cycle
MIX : Real ≝ 0.2 Mixing parameter
MIXOP : Real (optional)
VXC : AnyOf(VWN,MJW,VBH,PBE,PW92,EV-GGA,BJ,MBJ) ≝ VWN
Possible values:
VWN Vosko, Wilk, Nusair
MJW Janak, Williams, Moruzzigit g
VBH von Barth, Hedin
PBE Perdew, Burke, Ernzendorfer GGA
PW92 Perdew Wang
EV-GGA Engel and Vosko GGA
BJ Becke-Johnson
MBJ modified Becke-Johnson
parametrisation of the exchange-correlation potential
ALG : AnyOf(BROYDEN2,TCHEBY) ≝ BROYDEN2
Possible values:
BROYDEN2 Broyden’s second method
TCHEBY Tchebychev
Mixing algorithm
EFGUESS : Real (optional) Skip the Fermi energy search in the beginning.
TOL : Real ≝ 1e-05 Tolerance threshold for the mixing algorithm
ISTBRY : Integer ≝ 1 Start Broyden after ISTBRY iterations
FULLPOT : Flag ≝ False Non-spherical callculation (full-potential) instead of ASA
ITDEPT : Integer ≝ 40 Iteration depth for Broyden algorithm (length of used history)
QION : Array(of Real) (optional) Guess for the ionic charges Qt for atomic types
MSPIN : Array(of Real) (optional) Guess for the magnetic moment μ_{spin,t} for atomic types
USEVMATT : Flag ≝ False Set up the starting potential using the original Mattheissconstruction for the potential V instead of the charge density
SECTION TASK contains:
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TASK : FixedValue(JXC) ≝ JXC
CLURAD : Real ≝ 2.2 The radius of a sphere restricting the cluster
of atoms for which the exchange coupling
constants will be calculated
SECTION SITES contains:
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NL : Array(of Integer) ≝ [3] Angula momentum cutoff (the first discarded l-space)
Expert options:
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SECTION MODE (optional, expert) contains:
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MODE : AnyOf(NREL,SREL,SP-SREL) (optional)
Possible values:
NREL work in the nonrelativistic mode
SREL work in the scalar-relativistic mode
SP-SREL work in the spin-polarized scalar-relativistic mode
Using this option you can switch on the spin polarization and relativistic mode. If its not set (or set to FREL), the full relativity mode is used.
LLOYD : Flag ≝ False Use LLoyd formula for scattering operator. It can improve the accuracy of the Fermi energy.
MDIR : Array(of Real of length 3) ≝ [1. 0. 0.] (optional, add non-default, array) Common magnetisation direction vector with x, y and z in Cartesian coordinates. The normalisation is arbitrary.
C : Real ≝ 1.0 (optional, add non-default, array) Scale the speed of light for a given atom type.
SOC : Real ≝ 1.0 (optional, add non-default, array) Scale the strength of the spin-orbit coupling for atom type.
This section contains options that describe, how to consider relativity and/or spin. If the MODE is not specified otherwise the programs of the SPRKKR-package assume that a magnetic system should be treated in a fully relativistic way. By setting the parameter SP-SREL a slightly faster scalar relativistic calculation can be done instead for a magnetic system.
SECTION STRCONST (optional, expert) contains:
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ETA : Real (optional) Ewald parameter
RMAX : Real (optional) Convergency radius in real space
GMAX : Real (optional) Convergency radius in reciprocal space
The calculation of the ~k-dependent KKR structure constant matrix G(~k, E) is controlled by
three convergence parameters. ETA determines the relative weight of the real and reciprocal
space lattice sums, that are determined by the convergence radii RMAX and GMAX, respec-
tively. These convergence parameters have to be optimised anew if the lattice structure, the
lattice parameter or the energy or ~k-range used is changed. This is done by the program if
no values are applied via the input file. In some cases, in particular if one works at high
energies, it might be necessery to set the convergence by hand. For this purpose one can start
from the values set by kkrgen or kkrscf (see the output file).
Module Attributes
DOS task input parameters definition |