Data relating to calculations of chemical softness for adsorbed molecules (benzene, nitrobenzene, anisole) on the Pt{111} surface. Calculations were performed using the CASTEP and OptaDOS codes and the dataset contains input and output files for these. Also in-house code used in the analysis of the data (cross-correlation of density of states data for differently charges systems, and topological analysis of charge density) is provided. Detailed descriptions are included in multiple separate readme files to be found within the dataset.