Microcontinuum field theories, including Micromorphic theory, Microstructure theory, Micropolar theory, Cosserat theory, nonlocal theory and couple stress theory, are the extensions of the classical field theories for the applications in microscopic space and time scales. They have been expected to overlap atomic model at microscale and encompass classical continuum mechanics at macroscale. This work provides an atomic viewpoint to examine the physical foundations of those well-established microcontinuum theories, and to justify their applicability through lattice dynamics and molecular dynamics.