zero continuously [@Shimada:2018fp]. Throughout this study, the mass, length, and energy scales are measured in units of $m$, $\sigma$, $\varepsilon_\mathrm{LJ}$, respectively. The temperature is measured by $\varepsilon_\mathrm{LJ}/k_\mathrm{B}$ ($k_\mathrm{B}$ is the Boltzmann constant). Secondly, sequential monomer-beads along the polymeric chain are connected by a finitely extensible nonlinear elastic (FENE) potential: $$U_\mathrm{FENE}(r) =
\left\{ 
\begin{aligned}
& -\frac{\varepsilon_\mathrm{FENE}}{2} R_0^2 \ln \left[ 1 - \left(
 \frac{r}{R_0} \right)^{2} \right] & (r \le R_0), \\
& \infty & (r > R_0),
\end{aligned} 
\right.
\label{eq:FENE}$$ where $\varepsilon_\mathrm{FENE}$ is the energy scale of the FENE potential, and $R_0$ is the maximum length of the FENE bond. Their values are defined as $\varepsilon_\mathrm{FENE} = 30$ and $R_0 = 1.5$, according to Ref. [@Milkus:2018ha]. Finally, three consecutive monomer beads along the chain interact via the bending potential defined as follows: $$U_\mathrm{bend}(\theta) = \varepsilon_\mathrm{bend} \left[ 1 - \cos(\theta -
                          \theta_0) \right],
\label{eq:bend}$$ where $\theta$ is the angle formed by three consecutive beads, and $\varepsilon_\mathrm{bend}$ is the associated energy scale. This potential intends to stabilize the angle $\theta$ at $\theta_0$ that we set as $\theta_0 = 109.5^\circ$. Here, the value of $\varepsilon_\mathrm{bend}$ in a wide range from $\varepsilon_\mathrm{bend} = 10^{-3}$ to $10^4$, and the effects of the bending rigidity on the vibrational 