All the experimental results were acquired using a commercial low-temperature scanning tunneling microscope (Scienta-Omicron) operating under ultra-high-vacuum (UHV) conditions. The base pressure for measurements was below 1E-10 mbar with a sample temperature of 4.3 Cl-functionalization of the tip was performed on Au(111) following the procedure as described by Lawrence et al. On Au(110) Cl-terminated tips were achieved similarly by approaching the STM metal tip over an NaCl island by 420 pm from starting feedback parameters of 20 mV/100 pA. A clear enhancement of the imaging resolution and the appearance of a "hole-like" trace at the missing Cl position evidence the Cl-functionalization (Figure ). dIdV measurements were performed using a lock-in modulator with an oscillation frequency of 827 Hz and amplitude of 20-30 mV. STM images were analyzed using WSxM.