Van der Waals Interactions and Radiative Thermal Energy Exchange among Molecules and Macroscopic Bodies*

We present a theoretical framework that captures rich quantum and thermal electromagnetic phenomena arising from the coupling of charge (electromagnetic) and vibrational (phononic) fluctuations, including van der Waals interactions and radiative heat transfer among complex molecules and macroscopic objects. Our approach captures atomistic treatments of molecular electronic and vibrational response functions along with continuum models of macroscopic, long-range electromagnetic effects, combining techniques from ab-initio density functional theory (DFT) and classical electromagnetism to describe fluctuation phenomena at wavelengths and separations where the atomism of larger bodies, in contrast to those of molecules, can be neglected, but where the shapes of these objects plays an important role on their electromagnetic response. As a proof of concept, we make predictions of van der Waals interactions and thermal energy transfer among molecules in proximity to metallic and polar-dielectric surfaces that deviate significantly from previous theoretical treatments.