Mode-coupling theory predictions for a limited valency attractive square well model

Recently we have studied, using numerical simulations, a limited valency model, i.e. an attractive square well model with a constraint on the maximum number of bonded neighbours. Studying a large region of temperatures T and packing fractions ϕ, we have estimated the location of the liquid–gas phase separation spinodal and the loci of dynamic arrest, where the system is trapped in a disordered non-ergodic state. Two distinct arrest lines for the system are present in the system: a (repulsive) glass line at high packing fraction, and a gel line at low ϕ and T . The former is essentially vertical (ϕ controlled), while the latter is rather horizontal ( T controlled) in the (ϕ– T ) plane. We here complement the molecular dynamics results with mode coupling theory calculations, using the numerical structure factors as input. We find that the theory predicts a repulsive glass line—in satisfactory agreement with the simulation results—and an attractive glass line, which appears to be unrelated to the gel line.