Character string (e.g., van Genuchten, porosity, m^3/s, Roe Superbee)
Integer (no alpha characters, special characters, or punctuation) (e.g., 1, 32, 195634)
Real (decimal points and exponential notation allowed) (e.g., 0, 0.0, 1.e-12, 1.E+3, 2.345)
Keyword (exact formatting required) (e.g., file, ~Solution Control Card, binary file)
~Gas Species Card
Number of Gas Species,Gas Species Molecular Diffusion Coefficient,Units (m2/s),
Repeat for Number of Gas Species
Gas Species Name,