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

نویسنده

  • E. Zaccarelli
چکیده

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 neighbors. 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.

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تاریخ انتشار 2006