I want to create such compound.
COMPOUND 4.0 BISMUTH 3.0 GERMANIY 12.0 OXYGENBGO
Why in Flair GUI it shows BGO with red color ?
It is difficult to answer you if you don’t share your .flair file.
Did you add a MATERIAL card for BGO?
I recommend you to have a look at the lecture on materials from the last course.