Determining the individual electromagnetic field of single molecules like DNA, RNA, proteins, carbohydrates, and fats theoretically involves various physics principles. Techniques such as optical spectroscopy, including absorption and Raman scattering, can analyze these molecules at different frequencies, while nuclear magnetic resonance and electron magnetic resonance operate at radio frequencies. X-ray crystallography is also relevant for mapping electron density and atomic positions, contributing to understanding the electromagnetic properties of molecules. However, the original poster's definition of "electromagnetic field" remains unclear, leading to uncertainty in the discussion. Clarification from the OP is needed to refine the suggestions and approaches.