Mean first core radius as a function of initial cloud mass. The mean radius is calculated over the time from the onset of the first core formation until the second core formation. The circles indicate results from the simulation runs with a constant initial temperature of 10 K, whereas the diamonds, triangles, and crosses indicate results from the simulation runs with constant stability parameters M_BE ∕M₀ of 5.27e-01, 5.27e-02, and 5.27e-03 for the low-, intermediate-, and high-mass regimes, respectively.