This Cu EAM potential parameter file "Cu_u6.eam" was obtained from the LAMMPS distribution and is dated 2007-06-11. The description in the file header refers to this as the "universal 4" Cu functions, but the parameter file name is "u6". The potential is therefore identified as the "universal 6" form here in agreement with the file name. The file header cites a paper by Adams, Foiles and Wolfer from 1989.