The species program determines the initial linearization energies, the core-valence separation and the semi-core states from the tabulated data corresponding to the chemical elements. To this end, an atomic calculation (within the LDA as default) is performed and the eigenvalues are determined. The type of APW-like basis set (LAPW, APW+lo, …) as well as several cutoff parameters can be specified as inputs, which are documented in the species.input file below. Some input parameters
are not of an immediate physical importance, however they can be adjusted for experimenting with the basis set. The adjustment of these parameters requires in-depth knowledge of the APW-like basis set. Usually the species files located in exciting/species/ are selected for calculations and (if necessary) modified by hand.
the species program takes two inputs:
- the species.dat
- species.input
It then writes the species definitions into the working directory
The spesies.input File
!---------------------------------------------------!
! APW+lo (semicore-local orbitals and small lo) !
!---------------------------------------------------!
apwdescr
'APW+lo'
suffix
''
apw
1
0 .false.
apwx
1
0 .true.
locorb
.true.
locorbsc
.true.
searchlocorb
.true.
!------------------------------------------------------------------------------!
! Documentation of input parameters
! input species; if empty all elements of species.dat file will be generated
!inspecies
! 'Si'
! core-valence cut-off energy (Hartree); default is -3.5d0
!ecvcut
! -3.5d0
! semi-core cut-off energy (Hartree); default is -0.35d0
!esccut
! -0.35d0
! string for description of method, written to the species files
!apwdescr
! 'APW testing basis set'
! string contained in filename appended after the species symbol string
!suffix
! 'SLAPW4-test'
! APW-block
! dm ........ matching order
! ve ........ if .true., the lin. energy is allowed to vary during the
! SCF cycle, i.e. it is searched for an optimal value - if this
! value is not found the default value is used
!apw
! 2 : apword
! 0 .false. : dm, ve
! 1 .false.
! apwx-block
! This is the APW block for the exceptions
!apwx
! 2 : apword
! 0 .true. : dm, ve
! 1 .true
! .true. if local orbitals (small lo, i.e. non-semicore states) are to be
! included
!locorb
! .true.
! .true. if semi-core states are to be included as local orbitals (captial LO)
!locorbsc
! .true.
! .true. if linearization energies for physical meaningful l-values are allowed
! to be searched during the SCF cycle for local orbitals (lo)
!searchlocorb
! .true.
! energy convergence tolerance for Dirac equation solver
!epsedirac
! 1.d-10
! potential convergence tolerance for SCF of atom
!epspot
! 1.d-7
!------------------------------------------------------------------------------!
! Parameter sets for default cutoffs for atomistic calculation.
! parameterset corresponding to some of the shipped species-files
!epsedirac
! 1.d-10
!epspot
! 1.d-7
! parameterset corresponding to original source code of species program -
! this is the default setting
!epsedirac
! 1.d-11
!epspot
! 1.d-6
