The valence bands of KHgC(4) and KHgC(8).

We present core level and valence band photoemission spectra of stages 1 and 2 potassium-mercury intercalated graphite, taken using a monochromatic x-ray source. Besides confirming earlier-measured core level shifts we have new evidence, in the core level lineshapes and in the valence photoemission intensities, regarding the electronic nature of these compounds. The core level data suggests greater occupancy of states with K 4s character than in the binary compound KC(8), consistent with the higher c-axis compressibility of these compounds. The valence band data indicate higher occupancy of states with Hg 6s character in the stage-two ternary compound than in the stage-one compound. This suggests the Hg 6s electrons may play an important role in the superconductivity of KHg-intercalated graphite, as the stage-two compound has a higher T(c) than the stage-one compound.