Whether the emissivity of different kinds of particles can be expressed by a single keyword

Hello developers!
My model contains two particles, particle 1 has emissivity of 0.81 and particle 2 has emissivity of 0.86. I now need to calculate a user-defined scalar based on the emissivity of each of these two particles. But I don’t know if there is any keyword that can indicate the emissivity of these two particles. Or is it possible to calculate a value based on the different particle phases using an if statement separately?

If the particle index is LL, the particle’ phase is stored in pijk(LL,5)
You can use a conditional bases on that. Make sure you have

 USE discretelement, only: pijk

at the top of your routine so you can access pijk