The cards in this section either control module rdinp or are not associated with any particular module, and are used throughout the FEFF calculations. In either case, they begin influencing the calculations in rdinp. The ATOMS card is used to specify the absorbing atom and its environment (if atomic coordinates are not known, then the OVERLAP card can be used to construct approximate potentials). Without this structural information, no calculations can be done. The CONTROL card is used to selectively run parts of FEFF. The PRINT card controls which output files are written by the modules.