Kelvin Probe Force Microscopy (KPFM) is one of the newest scanning probe microscopy techniques, that enables us to obtain information about electrostatics and charge transfer on a surface, measured via very sharp tip moving above a sample. However, the theory behind the KPFM measurements and all physical interactions between the tip and sample are not fully understood, especially for very close scans. We plan to use density functional theory calculations to reveal the unknown physics of close KPFM scans. We will prepare multiscale simulation package for the KPFM, which will work on quantum theory level as well as simplified fast mechanistic model level and which will cover a wide range of experimental conditions. This work will enable us to get additional information about the physics going on the scanned sample from the KPFM measurements and to employ KPFM as an additional source of information for structural identification. Finally, it can lead to general theory for chemical resolution in scanning probe microscopy.