AddingReflection - adda-team/adda GitHub Wiki

Here "reflection" denotes the part of the total Green's tensor for two interacting dipoles, which comes from the surface. So if you want to implement a new formulation of the total Green's tensor, you may also consider the direct interaction.

All places in the code, where something should be added, are commented. These comments start with TO ADD NEW REFLECTION FORMULATION and contain detailed description; the text below is less detailed. Added code should be analogous to reflection formulations already present. The procedure is the following:

• Add new reflection term descriptor in the file const.h. Starting descriptor name with GR_ is recommended, as well as adding a descriptive comment.
• Add information about the new reflection formulation in the file param.c.
  • Modify string constants after PAR(int_surf) in the constant array options: add new argument to list {...} and its description to the next string.
  • Add one line to the else-if sequence in the function PARSE_FUNC(int_surf). If new formulation allows sub-arguments, process them here.
  • Take a look at the logic for interrelation between reflection formulations and perfectly conducting surface in function VariablesInterconnect and revise it, if needed.
  • Add a case to the relevant switch in the function PrintInfo.
• Main part of the code should be added to interaction.c.
  • Add functions that actually perform the calculation of the reflection term, according to the new formulae. At the end you need to have two functions according to the declarations ReflTerm_int and ReflTerm_real in interaction.h. There are two ways to proceed:
    • either (recommended) create one main function with the following declaration

      static inline void ReflTerm_<name>(double qvec[static 3],doublecomplex result[static 6])

      which works for double input vector. After the function definition you specify WRAPPERS_REFL(InterTerm_<name>), which automatically produces wrappers compatible with declarations in interaction.h.
    • or create two separate functions named ReflTerm_<name>_int and ReflTerm_<name>_real with declarations described in interaction.h. If the new formulation does not support arbitrary real input vector (e.g. it is based on tables), then use NO_REAL_WRAPPER(ReflTerm_<name>) instead of the real-input declaration.
  • Update assignment of function pointers in function InitInteraction. If new formulation requires initialization, add it here as well, preferably by a separate function. Also test for possible incompatibilities with other ADDA parameters, if any, and add an exception.
  • If you allocate any memory (for tables, etc.), free it in function FreeInteraction.

Please refer to section Interaction Term of the manual for general overview and precise definition of the reflection term inside ADDA.

If you add a new refletion formulation to ADDA according to the described procedure, please consider contributing your code to be incorporated in future releases.