J. Yoshinobu et al., DIRECT OBSERVATION OF MOLECULE-SUBSTRATE ANTIBONDING STATES NEAR THE FERMI-LEVEL IN PD(110)-C(4 X 2)-BENZENE, Physical review letters, 79(20), 1997, pp. 3942-3945
Evidence for a molecule-substrate hybridized state near the Fermi leve
l E-F is presented for Pd(110)-c(4 x 2)-benzene. Observed images of ad
sorbed benzene near E-F by scanning tunneling microscopy consist of tw
o elongated protrusions separated by a single nodal depression with C-
2 symmetry. The existence of a benzene derived state near E-F is also
observed by metastable atom electron spectroscopy, and it is assigned
to the antibonding states between the 1e(1g) molecular orbital of benz
ene and the Pd 4d orbitals by ab initio molecular orbital calculations
.