IBM scientists first to image the anatomy of a molecule
Imaging the structure of molecules with atomic resolution was achieved by noncontact atomic force microscopy (NC-AFM). Our low-temperature STM/AFM is based on a qPlus sensor design  and is operated in an ultrahigh vacuum at a temperature of 5 K.
The key step to achieving atomic resolution on molecules is the functionalization of the microscope’s tip apex with a suitable, atomically well-defined termination, such as a CO molecule . In this case, atomic manipulation techniques are essential for the controlled buildup of the tip used for AFM imaging .
We also perform density functional theory (DFT) calculations to elucidate the physical origins of the contrast observed. The calculations reveal that the Pauli repulsion is the source of the atomic resolution  and yield insights into the important role of the tip functionalization .
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