Molecular adsorption of $CH3CN$ and $C5H5N$ on $Si(111)7×7$

The adsorption structures of $CH3CN$ and $C5H5N$ molecules on the $Si(111)7×7$ surface have been studied by a low temperature scanning tunneling microscopy. These molecular adsorption sites are across the dimer row of the $Si(111)7×7$ surface. These molecular adsorption structures can be explained, assuming the dipole–dipole interaction between the molecules and the $Si(111)7×7$ surface.