Variable step radial ordering in carbon onions

We analyse the radial distribution of atoms in carbon onions optimised using a combination of classical molecular dynamics and density functional theory. X-ray diffractograms of thermally annealed nanodiamonds are also exploited together with high-resolution transmission electron microscopy data published elsewhere. The internal radial ordering of atoms inside the onions was determined showing a gradual change of intershell separation as a function of radius. This change may result in a twisted internal structure of the onions. The influence of atomic defects appearing in the shells altering their curvature on the formation of twisted onions is discussed.