▎ 摘　　要

The defects in graphene have significant influence on its properties. However, there are few literatures about how these defects influence nuclear magnetic resonance parameters of C-13 nuclei. In this work, we provide first-principles quantum calculations of NMR parameters of three types of defects: Stone-Wales, double vacancy, and single vacancy in modeled graphene nanoflakes. The calculated C-13 chemical shifts and nuclear spin-spin coupling constants are significantly influenced by different defects. For single vacancy model, the averages and standard deviations of chemical shifts of carbon nuclei of defected circle always are much higher than those in the Stone-Wales and double vacancy defects. For one-bond spin-spin coupling constants of C-13-C-13 in the defected circles of different models, the averages and the standard deviations also have similar trends, but the differences among these models are not large. Our results indicate that every kind of defect shows a different pattern of the NMR parameters from the others, which may be used to identify the type of defect in graphene.