He is noted for his pioneering contributions to the application of informatics techniques and the development of innovative accelerated computational methods for design and discovery and characterization of novel materials. Professor Rajan is the leading proponent of the field of Materials Informatics. His research is centered on the application of information science and data intensive methodologies for the discovery, characterization and modeling of materials. Along with computational studies, he is a leader in the field of advancing quantitative methods for the interpretation of nanoscale chemical imaging techniques such as, atom probe tomography.