%0 Journal Article %T Crystal structure of 2-ethyl-4-methyl-1-(2-oxido-3,4-dioxo-cyclo-but-1-en-1-yl)-1H-imidazol-3-ium %A Ahmet Bulut %A Iclal Bulut %A Ufuk Korkmaz %J Archive of "Acta Crystallographica Section E: Crystallographic Communications". %D 2016 %R 10.1107/S2056989016009725 %K crystal structure %K squarene %K hydrogen bonding %K quantum chemical calculations %K non-linear optical properties %U https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4992924/