\(\renewcommand{\AA}{\text{Å}}\)
fix_modify AtC gradients command
Syntax
fix_modify <AtC fixID> gradients <add|delete> <list_of_fields>
AtC fixID = ID of fix atc instance
gradients = name of the AtC sub-command
add or delete = select whether to add or delete calculation of gradients for the listed output fields
list_of_fields = one or more of the fields listed below:
density : mass per unit volume
displacement : displacement vector
momentum : momentum per unit volume
velocity : defined by momentum divided by density
projected_velocity : simple kernel estimation of atomic velocities
temperature : temperature derived from the relative atomic kinetic energy
kinetic_temperature : temperature derived from the full kinetic energy
number_density : simple kernel estimation of number of atoms per unit volume
stress : Cauchy stress tensor for eulerian analysis (atom_element_map), or first Piola-Kirchhoff stress tensor for lagrangian analysis
transformed_stress : first Piola-Kirchhoff stress tensor for eulerian analysis (atom_element_map), or Cauchy stress tensor for lagrangian analysis
heat_flux : spatial heat flux vector for eulerian, or referential heat flux vector for lagrangian
potential_energy : potential energy per unit volume
kinetic_energy : kinetic energy per unit volume
thermal_energy : thermal energy (kinetic energy - continuum kinetic energy) per unit volume
internal_energy : total internal energy (potential + thermal) per unit volume
energy : total energy (potential + kinetic) per unit volume
number_density : number of atoms per unit volume
eshelby_stress : configurational stress (energy-momentum) tensor defined by [Eshelby]
vacancy_concentration : volume fraction of vacancy content
type_concentration : volume fraction of a specific atom type
Examples
fix_modify AtC gradients add temperature velocity stress
fix_modify AtC gradients delete velocity
Description
Requests calculation and output of gradients of the fields from the AtC transfer class. These gradients will be with regard to spatial or material coordinate for Eulerian or Lagrangian analysis, respectively, as specified by fix_modify AtC atom_element_map
Restrictions
Must be used with fix atc hardy.
Default
None.