fix_modify AtC control thermal

syntax

fix_modify AtC control thermal <control_type> <optional_args>

• control_type (string) = none | rescale | hoover | flux
  

fix_modify AtC control thermal rescale <frequency>

• frequency (int) = time step frequency for applying velocity rescaling
  

fix_modify AtC control thermal hoover

fix_modify AtC control thermal flux <boundary_integration_type(optional)> <face_set_id(optional)>

• boundary_integration_type (string) = faceset | interpolate
  
• face_set_id (string), optional = id of boundary face set, if not specified (or not possible when the atomic domain does not line up with mesh boundaries) defaults to an atomic-quadrature approximate evaulation, does not work with interpolate
  

examples

fix_modify AtC control thermal none
fix_modify AtC control thermal rescale 10
fix_modify AtC control thermal hoover
fix_modify AtC control thermal flux
fix_modify AtC control thermal flux faceset bndy_faces

description

Sets the energy exchange mechansim from the finite elements to the atoms, managed through a control algorithm. Rescale computes a scale factor for each atom to match the finite element temperature. Hoover is a Gaussian least-constraint isokinetic thermostat enforces that the nodal restricted atomic temperature matches the finite element temperature. Flux is a similar mode, but rather adds energy to the atoms based on conservation of energy. Hoover and flux allows the prescription of sources or fixed temperatures on the atoms.

restrictions

only for be used with specific transfers : thermal (rescale, hoover, flux), two_temperature (flux)
rescale not valid with time filtering activated

related

default

none
rescale frequency is 1
flux boundary_integration_type is interpolate