Exoplanets smaller than Neptune, terrestrial exoplanets and sub-Neptunes, are ubiquitous in the galaxy. With advanced telescopes such as the James Webb Space Telescope, the atmospheric spectra of these planets are being retrieved, which will eventually provide insights into their atmospheric compositions. However, understanding the planet’s surface conditions, interior structure, and its evolution through time also requires the consideration of mineralogy and interior structure, mantle evolution, and volatile exchange between interior and atmosphere. To this interdisciplinary session, we invite contributions from numerical modeling, laboratory experimental studies, as well as observations of exoplanets and their atmospheres. We particularly welcome innovative work that highlights the impact of the study on predicting the evolution and on the characterisation of exoplanets. Applications range from magma ocean planets to planets within the habitable zone and from Earth-sized planets to sub-Neptunes. Contributions include geophysical and geochemical modeling, thermochemical equilibrium and kinetics, photochemistry, volatile outgassing and recycling, as well as high-pressure high-temperature laboratory experiments. Let us bridge the gap between prediction and observation of small to intermediate-sized exoplanets!