Stable $π$-radical 2,2-diphenyl-1-picrylhydrazyl (DPPH) adsorbed at the elbows of $22\times\sqrt{3}$ reconstructed Au(111)

Stable $π$-radical 2,2-diphenyl-1-picrylhydrazyl (DPPH) adsorbed at the elbows of $22\times\sqrt{3}$ reconstructed Au(111)