# Data Exchange

Commands that exchange data between the driver and the engine.

Command Name | Description
------------ | -----------
[CDENSITY](CDENSITY) | Exchange Cartesian coordinates for grid points.
[CELL](CELL) | Exchange cell vectors for simulation boxes.
[CELL_DISPL](CELL_DISPL) | Exchange cell displacement vectors for simulation boxes.
[CHARGES](CHARGES) | Exchange atomic charge information.
[CLATTICE](CLATTICE) | Send lattice coordinates.
[COORDS](COORDS) | Exchange atomic coordinate information.
[CPOTENTIAL](CPOTENTIAL) | Send Cartesian coordinates of grid points.
[DENSITY](DENSITY) | Retrieve electronic density information.
[DIMENSIONS](DIMENSIONS) | Retrieve simulation cell dimensionality (periodic or non-periodic).
[ELECT_MULT](ELECT_MULT) | Exchange electronic multiplicity.
[ELEMENTS](ELEMENTS) | Exchange atomic element information.
[ENERGY](ENERGY) | Receive total energy information.
[FORCES](FORCES) | Exchange atomic forces information.
[KE](KE) | Receive total kinetic energy.
[KE_ELEC](KE_ELEC) | Receive electronic kinetic energy.
[KE_NUC](KE_NUC) | Receive nuclear kinetic energy.
[LABELS](LABELS) | Receive a label for each atom in the system.
[LATTICE](LATTICE) | Send lattice point charges.
[LATTICE_FORCES](LATTICE_FORCES) | Receive lattice forces.
[MASSES](MASSES) | Retrieve atom masses.
[MONKHORST-PACK_NPOINTS](MONKHORST-PACK_NPOINTS) | Send number of points for a Monkhorst-Pack grid.
[MONKHORST-PACK_SHIFT](MONKHORST-PACK_SHIFT) | Send Monkhorst-Pack grid shift.
[NATOMS](NATOMS) | Receive number of atoms.
[NDENSITY](NDENSITY) | Receive number of points for electronic density on a grid.
[NLATTICE](NLATTICE) | Send number of lattice points.
[NPOTENTIAL](NPOTENTIAL) | Send the number of potential grid points.
[PE](PE) | Receive total potential energy.
[PE_ELEC](PE_ELEC) | Receive electronic potential energy.
[PE_NUC](PE_NUC) | Receive nuclear potential energy.
[POTENTIAL](POTENTIAL) | Send potential grid values.
[SPIN_POLARIZATION](SPIN_POLARIZATION) | Exchange spin polarization information.
[STRESS](STRESS) | Exchange virial stress tensor.
[TOTCHARGE](TOTCHARGE) | Exchange total charge information
[VELOCITES](VELOCITES) | Exchange atomic velocities.


```{toctree}
:hidden:

CDENSITY
CELL
CELL_DISPL
CHARGES
CLATTICE
COORDS
CPOTENTIAL
DENSITY
DIMENSIONS
ELECT_MULT
ELEMENTS
ENERGY
FORCES
KE
KE_ELEC
KE_NUC
LABELS
LATTICE
LATTICE_FORCES
MASSES
MONKHORST-PACK_NPOINTS
MONKHORST-PACK_SHIFT
NATOMS
NDENSITY
NLATTICE
NPOTENTIAL
PE
PE_ELEC
PE_NUC
POTENTIAL
SPIN_POLARIZATION
STRESS
TOTCHARGE
VELOCITES