Figure 4. The polycrystalline estimate of the dielectric constant $\left({\mathit{\epsilon }}_{poly}\right)$.

The x-axis represents the DFT-GGA+U band gap values (E_g) obtained from the Materials Project website. There is a total of 1,056 data points for inorganic compounds. The red data points refer to values for polymers calculated by Huan et al.³¹ Red and green lines represent the figures of merit $\left({\mathit{\epsilon }}_{poly}\cdot E_g\right)$ and $\left(\sqrt{{\mathit{\epsilon }}_{poly}}\cdot E_g\right)$ respectively. The formulas of promising compounds with ${\mathit{\epsilon }}_{poly}\cdot E_g\mathrm{>16}$ and $\sqrt{{\mathit{\epsilon }}_{poly}}\cdot E_g\mathrm{>160}$, are shown on the graph. HfO₂, SiO₂ and polyethylene are also shown for information.