In this chapter, the structural and thermodynamic properties of hybrid perovskites are reviewed within the theoretical perspective of classical molecular dynamics applied to a material with an ionic character. An overview of the crystalline structural properties of both inorganic and hybrid perovskites is given using the concepts of tolerance factor and effective ionic radii for organic and inorganic ions. The simple ionic 2description of the material provides an effective representation of interatomic forces reproducing the fundamental finite-temperature properties of the hybrid perovskites including orthorhombic-to-tetragonal transitions, cation dynamics, molecular entropy, vibrational properties, and thermal conductivity.