Point and complex defects and doping play important roles in the mechanical, physical properties and functionality of crystalline materials such as carbides. First-principle calculations of defects/doping based on density functional theory have been widely used as an effective tool for studying the influence of defect and doping elements, which is important for understanding the evolution of precipitated carbides and the development of high-performance carbides. In this study, first principle method is adapted to establish data for two typical carbides - Ni4C and Mo2C in 2D and 3D structures. A systematic approach has been developed for studying and analyzing the effects of a range of doping elements and different types of defects on the mechanical, electronic and magnetic properties.

Calculations show that there is an enhancement in magnetism of Mo2C structure when dopped with Co and Mn, which may be due to the doping elements of changing the electronic structure of Mo2C, introducing local magnetic moments. Data with Co and Mn doping in Ni4C also indicates an increase of the magnetic moment and enhancement of the magnetic performance. In addition, change of magnetic data of Mo2C is observed with some types of vacancy defects and asymmetric structure. The comparative analysis of data for 2D and 3D structures of Mo2C show that the 2D structure has different characteristics from the 3d structure when doped. These results further contribute to the understanding of effects of defects and doping elements on the mechanical and physical properties in particular magnetism of carbides. The potential link between the data to the understanding of carbide formation and their use in new emerging areas is analysed. The issues and use of the data in integrated approaches combining modelling, experimental and data analysis is discussed.