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The physical and electronic structure of the dispersed and (2× 2) phases of K/graphite have been characterized by valence and core-level photoemission. Charge transfer from K to graphite is found to occur at all coverages, and includes transfer of charge to the second graphite layer. A rigid band description is reasonably successful in describing important aspects of the data, and our results are consistent with a shift of approximately 0.4 eV in the surface graphite layer for both phases. The C 1 s line shape and binding-energy shift as a function of charge transfer can be understood qualitatively by taking into account rigid band effects and the effects of a core hole on the density of states. For the (2× 2) phase the metallic overlayer contributes extrinsic satellites to the C 1 s line shape. The K 3 p spectrum is strongly affected by the overlayer phase, and in addition indicates very little variation in the substrate charge …