Collapse and revival dynamics for P_m4(α,t) with ω₁ = 0.15ω, ω₂ = 0.075ω, α = 3, β₁ = 0.16 and β₂ = 0.14 [(a) and (b)]; ω₁ = 0.15ω, ω₂ = 0.075ω, α = 3, and β₁ = β₂ = 0.14 [(c)].