The previous predicted cyclo- [18]-carbon, an sp-hybridized molecular carbon allotrope, was firstly synthesis and observed using atom manipulation technique on Cu(111) surface covered by bilayer NaCl at 5.0 K by K. Kaiser and co-workers in Aug. 2019. Their work raised immense attention from both experimental and theoretical scientists once published. Tian Lu and co-workers performed a series of detailed analyses into C18 molecule and its synthetic precursors based on density functional theory (DFT) calculations, verifying that the electronic structure of C18 has a dual-aromaticity feature and extended horizons to other properties of C18 and related precursors. G.