Oral, A.Grimble, R. A.Ozer, H. O.Hoffman, P. M.Pethica, J. B.2015-07-282015-07-2820010003-6951http://hdl.handle.net/11693/10944Quantitative force gradient images are obtained using a sub-angstrom amplitude, off-resonance lever oscillation method during scanning tunneling microscopy imaging. We report the direct observation of short-range bonds, and the measured short-range force interaction agrees well in magnitude and length scale with theoretical predictions for single bonds. Atomic resolution is shown to be associated with the presence of a prominent short-range contribution to the total force interaction. It is shown that the background longer-range interaction, whose relative magnitude depends on the tip structure, has a significant effect on the contrast observed at the atomic scale. (C) 2001 American Institute of Physics.EnglishScanning-tunneling-microscopyReactive SurfacesTipArticle10.1063/1.1389785