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Incorporating the tight-binding theory and the bond order–length–strength(BOLS) correlation into the X-ray photoelectron spectra of Ag(111)and (100) surfaces and the Auger electron spectra of Ag nanoparticlesdeposited on Al2O3and CeO2substrateshas led to quantitative information of the 3d5/2and thevalence binding energies of an isolated Ag atom and their shifts uponbulk, defect, surface, and nanocrystal formation. It is clarifiedthat the globally positive energy shifts originate from the undercoordination-inducedGoldschmidt–Pauling bond contraction and the associated localquantum entrapment and the heterocoordination-induced bond naturealteration at the particle–substrate interfaces. Perturbationto the Hamiltonian by atomic ill-coordination dictates the energyshift that is proportional to the bond energy at equilibrium. Theoreticalreproduction of the measured spectroscopic data derived that the 3d5/2energy of an isolated Ag atom shifts from 363.02 to 367.65eV and the valence band center from 0.36 to 8.32 eV upon bulk formation.The extended Wagner plots revealed the coefficients of valence rechargingand potential screening to be 1.21 and 1.56 for Ag interacting withAl2O3substrate and 1.15 and 1.50 for Ag withCeO2, respectively. Exercises exemplify the enhanced capabilitiesof XPS and AES in determining quantitative information regarding theevolution of the local bond length, bond energy, binding energy density,and atomic cohesive energy, with the coordination and chemical environment. [ABSTRACT FROM AUTHOR]