The unusual ability of nitrogen in functionalizing transition metals has tremendous implications to the nitride compounds for chemical, electronic, optical, mechanical, and tribological applications yet a consistent insight into the underneath mechanism remains yet a challenge. A combination of the density function theory and photoelectron spectroscopy revealed that the nitrogen atom prefers the tetrahedron bonding geometry in the Ti(0001) skin, which derives four additional valence density-of-states: the bonding electron pairs, nonbonding lone pairs, electronic holes, and antibonding dipoles. Dipole formation modulates the work function, electron–hole generation opens the bandgap, nonbonding interaction ensures the superlubricity of the N-Ti(0001) skin.