Gas datas for Radiation Model
 

For a radiation analysis with P1 model in FLUENT, in the materials menu, FLUENT wants to enter the absorption coefficient (1/m) and scattering coefficient (1/m) for CO2, CO gases. How can I find these values?
I've searched lots of sources (forums, e-books etc.) but I didn't find anything about it.
Could you show me a source (e-book or a data book or equations to calculate) to find the values?