Supporting data for "Correlation of Fe(II) spin state with Born effective charge and dielectric properties in [Fe(ptz)_6](BF_4)_2: a DFT study"

This data publication provides supporting data for the paper "Correlation of Fe(II) spin state with Born effective charge and dielectric properties in [Fe(ptz)_6](BF_4)_2: a DFT study" by Eric Cockayne. The crystal structures and the input parameters used for the density functional theory (DFT) calculations on rhombohedral high-spin and low-spin [Fe(ptz)_6](BF_4)_2 are provided. Outputs of the calculations are also provided: force constant matrices, phonon frequencies and eigenvectors, electronic and ionic dielectric tensors, and Born effective charge tensors for both systems.