where we introduced a coupling parameter for this more complicated system, λ k,n = 1 ϵ0V êk,n . While this is rigorous, its computational cost can quickly become enormous. This can be seen by a simple basis size analysis. For j molecules with l states and m modes with n Fock states, the basis size scales as l j n m . Due to this unfavorable exponential scaling, the generalized Tavis-Cummings Hamiltonian is a useful approximation to simulate these systems.