1. The problem statement, all variables and given/known data Find Condensation Temperature of ideal Bose gas with internal degrees of freedom. Assume only ground and first excited state of internal spectrum need to be taken into account. 2. Relevant equations 3. The attempt at a solution I know j(T) for internal degrees of motion is j(T) = 1 + exp(-e1/kT), but I have no idea how to put that into the partition function, or grand partition function to obtain the condensation temperature. Can anyone give me ideas on how to start and proceed? Thanks.