where `_C.species`, `_C.tracer` and `_C.testfields` are NIRVANA
where `_C.species`, `_C.tracer` and `_C.testfields` are NIRVANA
parameters (cf. [NIRVANA: Specification of main simulation parameters](https://gitlab.aip.de/ziegler/NIRVANA/-/wikis/3-NIRVANA-user-guide/3.2-User-interfaces#specification-of-main-simulations-parameters))
parameters (cf. [NIRVANA: Specification of main simulation parameters](https://gitlab.aip.de/ziegler/NIRVANA/-/wikis/3-NIRVANA-user-guide/3.2-User-interfaces#specification-of-main-simulation-parameters))
storing the number of species, number of tracers and number of
storing the number of species, number of tracers and number of