11. Multispecies Unit

**Figure 11.1:** The `Multispecies` unit directory tree.

FLASH has the ability to track multiple fluids, each of which can have its own properties. The Multispecies unit handles setting and querying on the properties of fluids, as well as some common operations on properties. The advection and normalization of species is described in the context of the Hydro unit in Chp:Hydrodynamics Unit.

Subsections

11.1 Defining Species
11.2 Initializing Species Information in Simulation_initSpecies
11.3 Specifying Constituent Elements of a Species
11.4 Alternative Method for Defining Species
11.5 Routine Descriptions
11.6 Example Usage
11.7 Unit Test