With the concourse of a variety of experimental techniques ͑neutron diffraction, x-ray photoelectron spectroscopy, 13 C nuclear magnetic resonance, electron microscopy, and Raman spectroscopy͒ and a combination of reverse Monte Carlo, molecular dynamics, and Monte Carlo simulations, we propose a model for the microscopic structure of a sample of carbon nanospheres obtained from chlorination of cobaltocene. The sample, which exhibits a high porosity, is shown to be formed by a series of interconnected sheets of graphene. Despite the large degree ͑Ϸ80%͒ of sp 2 hybridization shown by carbon atoms, there is a non-negligible amount of sp 3 -bonded carbons, some of them acting as links between graphene sheets. The transmission electron microscopy images simulated from the microscopic structure, which is extracted from the neutron diffraction data by a mixed reverse Monte Carlo-molecular dynamics/Monte Carlo procedure, agree remarkably well with the experimental results.