ADDA is a C software package to calculate scattering and absorption of electromagnetic waves by particles of arbitrary shape and composition using the discrete dipole approximation (DDA). The particles can be located in a homogeneous medium or near a plane substrate; emission (decay-rate) enhancement of point emitters can also be calculated. The main feature of ADDA is the ability to run on a multiprocessor system or multicore processors (parallelizing a single DDA simulation). It can also employ modern GPUs to accelerate computations. ADDA is intended to be a versatile tool, suitable for a wide variety of applications ranging from interstellar dust and atmospheric aerosols to metallic nanoparticles and biological cells. Its applicability is limited only by available computer resources.

This software is available under GNU GPL 3. Full source code, Windows binaries, and extensive documentation are available.

• Link (11 July 2018)