$3.7\times 10^{9}\,\tau$ time steps to make sure the chains are relaxed and the results are not artifact of the simulation under strong confinement.

![(color online) The number density distribution of the monomers inside the sphere with different degrees of confinement. The radius of the confining sphere in each case is (a) $49$, (b) $30$, (c) $20$, and (d) $14$ all in unit of $\sigma$. Here we have a mixture of extra-stiff long segments (Long), extra-stiff short (Short), normal-stiff short (Short-n), and Flexible polymer chains. By stiff, we mean intra-stiffness. Entropic effect shows how segregation occurs in both weak and strong confinements. For weak confinement, the flexible chain moves toward the boundary, (a-c), and for strong confinement, (d), we see segregation of longer segment chain at the periphery. The markers do not represent the whole data points, solely used for differentiation of curves. []{data-label="fig:N_dens"}](fig2.pdf){width=".48\textwidth"}

Results
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The monomer number density, $n\left(r\right)$, is defined based on the location of each monomer relative to the center of the sphere. We divide the volume into the concentric shells with thickness of $\Delta r=R/100$ and average the number of monomers in each shell. Fig. \[fig:N\_dens\] shows the normalized number densities for different confinement radii. In 