Phantom GRAPE is a SIMD-accelerated numerical library for N-body simulations of self-gravitating systems. It works on x86 microprocessors with the AVX, AVX2, and AVX-512 instruction sets.
Phantom GRAPE has two sets of APIs; one is for collisionless self-gravitating systems and compatible with that of GRAPE-5, and the other is for collisional systems and compatible with the GRAPE-6 API. The former API also has a capability to compute arbitrary-shaped forces with a cutoff radius which is necessary for PPPM and TreePM methods.
This library contains a numerical package 'quad_tree' to accelerate the calculation of the quadrupole terms in the Barnes-Hut tree method developed by Kodama & Ishiyama (2019) PASJ in press. The package can be found in the PG5 directory and be used as an extension of Phantom-GRAPE.
For more details, see our following papers;
Tanikawa, et al. (2013) New Astronomy, 19, 74-88 (arXiv:1203:4037)
Tanikawa, et al. (2012) New Astronomy, 17, 82-92 (arXiv:1104:2700)