In the MPcules database at the time of this writing, there is exactly one molecule with charge +1 and formula C 2 H 4 , so query output will contain a list with one entry. Due to the quantity of data included in the MPcules summary collection, we will not show the entire output, but it is worth illustrating how one can interact with the results of a query: Each property section consists of a data tab including the processed data from the sum-mary document, a methods tab describing how the data was obtained from DFT and postprocessing, and an API tab describing how users can programmatically access the data. For example, the data tab for the Partial Charges and Spins section (Figure ) consists of two drop-down menus to select the method for calculating charges and spins, a table of atomic