What's the difference between Korg.species and Korg.Species?

Short answer: you can always use Korg.Species like so: Korg.Species("C II"). Longer answer: they do the same thing, but the lower-case version can only be applied to string literals. Both of these are ways to constructing objects of type [Korg.Species](@ref), which is used to represent atom and molecules with specific charges, e.g. C II or neutral FeH.Korg.Speciesis the constructor, which acts like a normal function.Korg.speciesis a [non-standard string literal](https://docs.julialang.org/en/v1/manual/metaprogramming/#meta-non-standard-string-literals), which is used without parentheses, like this:Korg.species"Mg I"`. It can only be applied to string literals (things that you actually type out between quotes, not variables containing strings.) The string macro does the work of constructing the species object at compile time, which can make code much faster in specific circumstances.

Are Korg spectra bitwise reproducible?

Korg spectra should be bitwise reproducible under these conditions:

• Using a single thread (Julia's default configuration)
• Running on the same machine
• Using identical Korg and dependency versions
• Providing identical input parameters

When running with multiple threads, small numerical differences may occur due to floating-point operations being performed in different orders.