Interactions

Interactions

Section System
Type block

This input option controls the interactions between systems. It basically allows to select which systems will interact with another system through a given interaction type. The format of the block is the following:

%Namespace.Interactions
  interaction_type | interaction_mode | …
%

Here is an example to better understand how this works:

%SystemA.Interactions
  gravity | all_except | "SystemB"
%

This means that SystemA and all the systems that belong to the same namespace (i.e., all its subsystems) will interact through gravity with all interaction partners that are also able to interact through gravity, except with SystemB. Note that the opposite is not true so, although clearly unphysical, this will not prevent SystemB from feeling the gravity from SystemA (in Octopus the interactions are always one-sided).

NB: Each interaction type should only appear once in the block. Any further instances beyond the first will be ignored.

Available modes and interaction types:

Options:

• no_partners:
  (interaction mode) Do not interact with any partner.
  
• all_partners:
  (interaction mode) Interact with all available partners.
  
• only_partners:
  (interaction mode) Interact only with some specified partners. A list of partner names must be given.
  
• all_except:
  (interaction mode) Interact with all available partners except with some specified partners. A list of partner names to exclude must be given.
  
• gravity:
  (interaction type) Gravity interaction between two masses.
  
• lorentz_force:
  (interaction type) Lorentz force resulting from an EM field acting on a moving charge.
  
• coulomb_force:
  (interaction type) Coulomb force between two charged particles.
  
• linear_medium_to_em_field:
  (interaction type) Linear medium for propagation of EM fields.
  
• current_to_mxll_field:
  (interaction type) Drude dispersive linear medium for propagation of EM fields.
  
• maxwell_field_to_medium:
  (interaction type) Electric field resulting from the Maxwell solver.
  
• lennard_jones:
  (interaction type) Force resulting from a Lennard Jones potential between classical particles.