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
It then writes the species definitions into the working directory
The spesies.input File
! input species; if empty all elements of species.dat file will be generated inspecies '' ! string for description of method, written to the species files: simple, advanced apwdescr 'simple' ! string contained in filename appended after the species symbol string suffix '' ! Default APW-block (all states) ! 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. : dm, ve ! Custom APW-block (occupied states) apwx 1 : apword 0 .true. : dm, ve ! .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. ! .true. if also the first linearization energy (E_l) is to be searched for ! u and u_dot. in any case the linearization energy (E_lo) is searched fullsearchlocorbsc .true. ! core-valence cut-off energy (Hartree); default is -3.5d0 ecvcut -3.5d0 ! semi-core cut-off energy (Hartree); default is -0.5d0 esccut -0.5d0