Elastic properties
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The elastic properties of polymer glasses are studied by changing the strength of bending rigidity. An external strain is applied to the system at $T=0$, which enables to measure the corresponding elastic moduli. Specifically, the volume-changing bulk deformation and the volume-conserving shear deformation are applied, which provide the bulk modulus $K$ and the shear modulus $G$, respectively [@Mizuno_2013]. Figure \[fig3\] presents the values of $K$ and $G$ as functions of $\varepsilon_\mathrm{bend}$. Disordered systems exhibit large non-affine elastic responses [@Alexander_1998]. The elastic moduli, $M=K$ and $G$, are decomposed into affine moduli $M_\mathrm{A}$ and non-affine moduli $M_\mathrm{NA}$, i.e., $M =
M_\mathrm{A} - M_\mathrm{NA}$ [@Tanguy_2002; @Lemaitre_2006]. In Fig. \[fig3\], these affine and non-affine components are also presented.

First, the bulk modulus $K$ is analyzed for $L=50$ and presented Fig. \[fig3\]a. The affine component $K_\mathrm{A}$ decreases from $K_\mathrm{A} \simeq
155$ to $130$ as $\varepsilon_\mathrm{bend}$ changes from $1$ to $10^3$. The reduction of $K_\mathrm{A}$ is caused by the decrease of the density $\rho$ with the increasing $\varepsilon_\mathrm{bend}$ (see Fig. \[fig1\]b). In contrast, the non-affine component $K_\mathrm{NA}$ shows a non-monotonic dependence on the $\varepsilon_\mathrm{bend}$. In particular, $K_\mathrm{NA}$ slightly increases from $\varepsilon_\mathrm{bend} = 1$ to $30$, which is induced by the decrease of the 