Benchmark of a new multi-ion-species collision operator for δf Monte Carlo neoclassical simulation. - Shinsuke Satake; Motoki Nataka; Theerasarn Pianpanit; Hideo Sugama; Masanori Nunami; Seikichi Matsuoka; Seiji Ishiguro; Ryutaro Kanno (Comput. Phys. Commun., 2020)