Each of these partially cross-linked systems was heated up to 900 K at a rate of 10 K / ps, and then slowly cooled down to 50 K in 10 K decrements, applied at the same rate. After each temperature drop, each system was equilibrated in the NPT ensemble for 100 ps at a pressure of 1 atm using the Nosè-Hoover barostat with a relaxation time of 100 fs, allowing the volume and consequently the density to adapt (the convergence of the density is shown for one example system in Figure ). This equilibration was followed by 100 ps production runs, which were utilized for the determination of T g (Figure ). Density data was collected every 100 fs.