Particle attributes

You are here: Home > PIConGPU User Documentation > Particle attributes

---

Available Particle Attributes and Flags

The identifiers of all particle attributes and flags can be found in
include/picongpu/simulation_defines/param/ -> speciesAttributes.param.
They are used to define the species in
speciesDefinition.param by default or overwritten in one of the various examples.

Attribute name	Description
position_pic	relative in-cell position
momentum	momentum at time step t
momentumPrev	momentum at previous time step t-1 (only with the Radiation plugin)
weighting	number of particles inside macro particle
radiationFlag	value decides if particle undergoes radiation algorithm (only with the Radiation plugin)
globalCellIdx_pic	position in units of cells relative to the (moving) window origin

See Create a new attribute for a short guide on implementing your own particle attributes.

---

Particle flags are constant attributes that cannot be changed during the simulation runtime. They are pinned inseparably to the species. Some of their values are set in species.param

Flag name	Description
atomicNumbers	contains number of protons and electrons for nucleus / ion / atom species
effectiveAtomicNumbers	atomic core charge shielded by inner electrons, defined in ionizerConfig.param
boundElectrons	the number of bound electrons in the shells of ion / atom species
shape	the shape of the macro particles (CIC, TSC, PCS)
particlePusher	algorithm that moves the particles under effect of EM-fields
ionizer	ionization model
interpolation	field to particle interpolation model
current	current solver model

There are two other values that can be accessed by particle[<identifier>_]. The first can be identified by multiMask which encodes numerically if the thread "is" a particle or not and if so: if it leaves the supercell in a specific direction. The second is localCellIdx which describes the position of a particle inside a supercell by a linear index.
See the definition and usage in $PICSRC/include/libPMacc/particles/Identifier.hpp

Continue with Plugins.

---

From #142

What particle attributes are there and how can they be accessed?

• a picturesque "tree" of all the available namespaces, a short explanation of their substructure and where to find what