Table 2. Description of metadata keys.

Key	Datatype	Description
e_electronic	array	${\mathit{\epsilon }}_{ij}^{\infty }$—Dielectric tensor (electronic contribution)
e_total	array	${\mathit{\epsilon }}_{ij}$—Total dielectric tensor
poly_electronic	number	${\mathit{\epsilon }}_{poly}^{\infty }$—Polycrystalline dielectric constant estimate (electronic contribution)
poly_total	number	${\mathit{\epsilon }}_{poly}$—Polycrystalline dielectric constant estimate (total)
n	number	n—refractive index
band_gap	number	Band gap in the Materials Project database
pot_ferroelectric	boolean	if ‘True’ it signifies a potentially ferroelectric compound
meta	various	metadata—contains details about the structure and DFPT calculation