Adaptive semi-empirical model for non-contact atomic force microscopy

Non-contact atomic force microscope is a powerful tool to investigate the surface topography with atomic resolution. Here we propose a new approach to estimate the interaction between its tips and samples, which combines a semi-empirical model with density functional theory (DFT) calculations. The generated frequency shift images are consistent with the experiment for mapping organic molecules using CuCO, Cu, CuCl, and CuO_x tips. This approach achieves accuracy close to DFT calculation with much lower computational cost.