.. include:: /substitutions.rst .. _paramsection: List of PARAMETERS by section ============================= This page lists parameters for ViPErLEED by which section of ViPErLEED/TensErLEED they are (most) relevant for. Parameters may occur multiple times, and not all parameters are listed. See the :ref:`main PARAMETERS page` for a complete alphabetical list and other groupings. .. note:: While all parameters have a default value, parameters marked with a "**→**" usually require user input for simple but non-trivial systems. Initialization -------------- .. table:: :width: 100% :widths: 30 70 +----------------------------------+--------------------------------------------------------------------------------------------------------------+ | Parameter | Function | +==================================+==============================================================================================================+ | :ref:`BEAMINCIDENCE` | Incidence angle and direction of the electron beam in experiment | +----------------------------------+--------------------------------------------------------------------------------------------------------------+ | :ref:`BULK_LIKE_BELOW` | Onset of unrelaxed slab, for automatic detection of minimal bulk and bulk repeat | +----------------------------------+--------------------------------------------------------------------------------------------------------------+ | :ref:`BULK_REPEAT` | Thickness of the bulk repeat unit, or a bulk repeat vector | +----------------------------------+--------------------------------------------------------------------------------------------------------------+ | :ref:`ELEMENT_MIX` | Declare that sites in the :ref:`POSCAR` file can be occupied by different chemical elements | +----------------------------------+--------------------------------------------------------------------------------------------------------------+ | :ref:`LAYER_CUTS` | How to separate the :ref:`POSCAR` file into layers | +----------------------------------+--------------------------------------------------------------------------------------------------------------+ | **→** :ref:`N_BULK_LAYERS` | Define how many layers in the :ref:`POSCAR` file represent the bulk | +----------------------------------+--------------------------------------------------------------------------------------------------------------+ | **→** :ref:`SITEDEF` | Define which sites in the :ref:`POSCAR` file are special, i.e. have different vibrational amplitude | +----------------------------------+--------------------------------------------------------------------------------------------------------------+ | **→** :ref:`SUPERLATTICE` | The relationship between the surface and bulk unit cells | +----------------------------------+--------------------------------------------------------------------------------------------------------------+ | :ref:`SYMMETRIZE_INPUT` | Whether to move atoms in the :ref:`POSCAR` file to perfectly match the symmetry | +----------------------------------+--------------------------------------------------------------------------------------------------------------+ | :ref:`SYM_EPS` | Error tolerance during symmetry search | +----------------------------------+--------------------------------------------------------------------------------------------------------------+ | :ref:`ISYM` | Manually set a symmetry, or turn symmetry off | +----------------------------------+--------------------------------------------------------------------------------------------------------------+ | :ref:`SYMMETRY_FIND_ORI` | Whether the symmetry search should look for the highest-symmetry point. | +----------------------------------+--------------------------------------------------------------------------------------------------------------+ | :ref:`THEO_ENERGIES` | What energy range to calculate | +----------------------------------+--------------------------------------------------------------------------------------------------------------+ | :ref:`T_DEBYE` | Debye temperature of the system (only for automatically generating :ref:`VIBROCC`) | +----------------------------------+--------------------------------------------------------------------------------------------------------------+ | :ref:`T_EXPERIMENT` | Measurement temperature in experiment (only for automatically generating :ref:`VIBROCC`) | +----------------------------------+--------------------------------------------------------------------------------------------------------------+ | :ref:`VIBR_AMP_SCALE` | Scaling factor, only for automatically generating :ref:`VIBROCC` | +----------------------------------+--------------------------------------------------------------------------------------------------------------+ .. note:: Parameters setting the symmetry strongly affect all sections, but are not listed again below. Reference calculation --------------------- .. table:: :width: 100% :widths: 30 70 +----------------------------------+--------------------------------------------------------------------------------------------------------------+ | Parameter | Function | +==================================+==============================================================================================================+ | :ref:`ATTENUATION_EPS` | Cutoff for beam propagation | +----------------------------------+--------------------------------------------------------------------------------------------------------------+ | :ref:`BEAMINCIDENCE` | Incidence angle and direction of the electron beam in experiment | +----------------------------------+--------------------------------------------------------------------------------------------------------------+ | :ref:`BULKDOUBLEEPS` | Convergence criterion for bulk thickness in the TensErLEED calculation | +----------------------------------+--------------------------------------------------------------------------------------------------------------+ | :ref:`BULKDOUBLEITER` | Maximum bulk thickness in TensErLEED calculation | +----------------------------------+--------------------------------------------------------------------------------------------------------------+ | :ref:`BULK_REPEAT` | Thickness of the bulk repeat unit, or a bulk repeat vector | +----------------------------------+--------------------------------------------------------------------------------------------------------------+ | :ref:`ELEMENT_MIX` | Declare that sites in the :ref:`POSCAR` file can be occupied by different chemical elements | +----------------------------------+--------------------------------------------------------------------------------------------------------------+ | :ref:`FILWF` | The LEED filament work function | +----------------------------------+--------------------------------------------------------------------------------------------------------------+ | :ref:`KEEP_REFCALC_DIRS` | Toggle to keep the reference calculating execution directories | +----------------------------------+--------------------------------------------------------------------------------------------------------------+ | :ref:`LAYER_CUTS` | How to separate the :ref:`POSCAR` file into layers | +----------------------------------+--------------------------------------------------------------------------------------------------------------+ | :ref:`LMAX` | Maximum angular momentum number; usually determined via :ref:`PHASESHIFTMIN` | +----------------------------------+--------------------------------------------------------------------------------------------------------------+ | **→** :ref:`N_BULK_LAYERS` | Define how many layers in the :ref:`POSCAR` file represent the bulk | +----------------------------------+--------------------------------------------------------------------------------------------------------------+ | **→** :ref:`NCORES` | The number of CPUs to use | +----------------------------------+--------------------------------------------------------------------------------------------------------------+ | :ref:`PHASESHIFTMIN` | Cutoff in phaseshifts magnitudes to determine :ref:`LMAX` | +----------------------------------+--------------------------------------------------------------------------------------------------------------+ | :ref:`SCREEN_APERTURE` | The aperture of the acceptance cone of the LEED screen | +----------------------------------+--------------------------------------------------------------------------------------------------------------+ | **→** :ref:`SITEDEF` | Define which sites in the :ref:`POSCAR` file are special, i.e. have different vibrational amplitude | +----------------------------------+--------------------------------------------------------------------------------------------------------------+ | **→** :ref:`SUPERLATTICE` | The relationship between the surface and bulk unit cells | +----------------------------------+--------------------------------------------------------------------------------------------------------------+ | :ref:`TENSOR_OUTPUT` | Disable Tensor output for some or all layers | +----------------------------------+--------------------------------------------------------------------------------------------------------------+ | :ref:`THEO_ENERGIES` | What energy range to calculate | +----------------------------------+--------------------------------------------------------------------------------------------------------------+ | :ref:`V0_IMAG` | Imaginary part of the inner potential | +----------------------------------+--------------------------------------------------------------------------------------------------------------+ | :ref:`MUFTIN` | Real part of the inner potential | +----------------------------------+--------------------------------------------------------------------------------------------------------------+ | :ref:`v0_z_onset` | How far from the topmost atom the inner potential begins | +----------------------------------+--------------------------------------------------------------------------------------------------------------+ |R-factor| calculation ---------------------- .. table:: :width: 100% :widths: 30 70 +----------------------------------+----------------------------------------------------------------------------------------------------+ | Parameter | Function | +==================================+====================================================================================================+ | :ref:`BEAMINCIDENCE` | Incidence angle and direction of the electron beam in experiment | +----------------------------------+----------------------------------------------------------------------------------------------------+ | :ref:`IVSHIFTRANGE` | Range and step size for shifting experimental and theoretical curves during |R-factor| calculation | +----------------------------------+----------------------------------------------------------------------------------------------------+ | :ref:`PLOT_IV` | Change appearance of the |R-factor| plot files | +----------------------------------+----------------------------------------------------------------------------------------------------+ | :ref:`RFACTORTYPE` | Which definition of the |R factor| to use | +----------------------------------+----------------------------------------------------------------------------------------------------+ | :ref:`RFACTORSMOOTH` | How strongly experimental beams are smoothed | +----------------------------------+----------------------------------------------------------------------------------------------------+ | **→** :ref:`SUPERLATTICE` | The relationship between the surface and bulk unit cells | +----------------------------------+----------------------------------------------------------------------------------------------------+ | :ref:`THEO_ENERGIES` | What energy range to calculate | +----------------------------------+----------------------------------------------------------------------------------------------------+ | :ref:`V0_IMAG` | Imaginary part of the inner potential | +----------------------------------+----------------------------------------------------------------------------------------------------+ Delta-amplitudes calculation ---------------------------- Behavior is mainly governed by the :ref:`DISPLACEMENTS` file. Some relevant parameters are: .. table:: :width: 100% :widths: 30 70 +----------------------------------+--------------------------------------------------------------------------------------------------------------+ | Parameter | Function | +==================================+==============================================================================================================+ | :ref:`ELEMENT_MIX` | Declare that sites in the :ref:`POSCAR` file can be occupied by different chemical elements | +----------------------------------+--------------------------------------------------------------------------------------------------------------+ | :ref:`LMAX` | Maximum angular momentum number; usually determined via :ref:`PHASESHIFTMIN` | +----------------------------------+--------------------------------------------------------------------------------------------------------------+ | **→** :ref:`NCORES` | The number of CPUs to use | +----------------------------------+--------------------------------------------------------------------------------------------------------------+ | :ref:`PHASESHIFTMIN` | Cutoff in phaseshifts magnitudes to determine :ref:`LMAX` | +----------------------------------+--------------------------------------------------------------------------------------------------------------+ | **→** :ref:`SITEDEF` | Define which sites in the :ref:`POSCAR` file are special, i.e. have different vibrational amplitude | +----------------------------------+--------------------------------------------------------------------------------------------------------------+ | **→** :ref:`SUPERLATTICE` | The relationship between the surface and bulk unit cells | +----------------------------------+--------------------------------------------------------------------------------------------------------------+ | :ref:`TENSOR_INDEX` | Which Tensor files to use for the delta calculation and search | +----------------------------------+--------------------------------------------------------------------------------------------------------------+ | :ref:`THEO_ENERGIES` | What energy range to calculate | +----------------------------------+--------------------------------------------------------------------------------------------------------------+ Search ------ Behavior is also governed by the :ref:`DISPLACEMENTS` file. The most relevant parameters are: .. table:: :width: 100% :widths: 30 70 +----------------------------------+----------------------------------------------------------------------------------------------------+ | Parameter | Function | +==================================+====================================================================================================+ | :ref:`BEAMINCIDENCE` | Incidence angle and direction of the electron beam in experiment | +----------------------------------+----------------------------------------------------------------------------------------------------+ | :ref:`IVSHIFTRANGE` | Range and step size for shifting experimental and theoretical curves during |R-factor| calculation | +----------------------------------+----------------------------------------------------------------------------------------------------+ | :ref:`LOG_SEARCH` | Output the search log file (may be very large, mostly for debugging) | +----------------------------------+----------------------------------------------------------------------------------------------------+ | **→** :ref:`NCORES` | The number of CPUs to use | +----------------------------------+----------------------------------------------------------------------------------------------------+ | :ref:`RFACTORTYPE` | Which definition of the |R factor| to use | +----------------------------------+----------------------------------------------------------------------------------------------------+ | :ref:`RFACTORSMOOTH` | How strongly experimental beams are smoothed | +----------------------------------+----------------------------------------------------------------------------------------------------+ | :ref:`SEARCHBEAMS` | Whether to use |R factor| of integer, fractional, or all beams for the search | +----------------------------------+----------------------------------------------------------------------------------------------------+ | :ref:`SEARCH_CONVERGENCE` | Convergence criteria for the search, and convergence-dependent parameter control | +----------------------------------+----------------------------------------------------------------------------------------------------+ | :ref:`SEARCH_CULL` | Controls regular culling of worst-performing structures, and what to replace them with | +----------------------------------+----------------------------------------------------------------------------------------------------+ | :ref:`SEARCHGENMAX` | Maximum total number of generations that the search should run for | +----------------------------------+----------------------------------------------------------------------------------------------------+ | :ref:`SEARCHPOP` | Number of trial structures used in the search | +----------------------------------+----------------------------------------------------------------------------------------------------+ | :ref:`SEARCHSTART` | How to initialize the search population | +----------------------------------+----------------------------------------------------------------------------------------------------+ | :ref:`STOP` | Stop execution of ViPErLEED at next opportunity | +----------------------------------+----------------------------------------------------------------------------------------------------+ | :ref:`TENSOR_INDEX` | Which Tensor files to use for the delta calculation and search | +----------------------------------+----------------------------------------------------------------------------------------------------+ | :ref:`THEO_ENERGIES` | What energy range to calculate | +----------------------------------+----------------------------------------------------------------------------------------------------+ | :ref:`V0_IMAG` | Imaginary part of the inner potential | +----------------------------------+----------------------------------------------------------------------------------------------------+ Domain search ------------- As the :ref:`domain search` may involve all of the segments above, the parameters listed there are relevant. The following additional parameters affect domains specifically: .. table:: :width: 100% :widths: 30 70 +----------------------------------+------------------------------------------------------------------------------------------------------------------------------------------+ | Parameter | Function | +==================================+==========================================================================================================================================+ | :ref:`DOMAIN` | Define a domain for :ref:`calculations involving multiple coexisting structural domains` | +----------------------------------+------------------------------------------------------------------------------------------------------------------------------------------+ | :ref:`DOMAIN_STEP` | Step width for structural domain coverage during search | +----------------------------------+------------------------------------------------------------------------------------------------------------------------------------------+ | :ref:`SYMMETRY_CELL_TRANSFORM` | Relationship between a supercell and the primitive surface unit cell (only relevant for :ref:`domain calculations`) | +----------------------------------+------------------------------------------------------------------------------------------------------------------------------------------+