Interaction potential function for the deformation analysis of potassium dihydrogen phosphate using molecular dynamics simulation

Potassium dihydrogen phosphate (KDP) is an important nonlinear optical material which plays a core role in electro-optic switches and laser spectroscopy. However, KDP is also one of the most difficult-to-handle materials due to its fragility, unstable microstructure and complex mechanical behaviour. Molecular dynamics (MD) simulation is an appropriate method to explore the deformation mechanisms of the material at the atomic scale. However, the challenge is that there is not a suitable potential function for describing the mechanical behaviour of KDP by using MD simulation. This paper successfully developed a potential function, which enables such insightful investigations. It was found that the established potential function can reliably predict the mechanical properties of KDP including its modulus in different crystal directions and structural changes under various loading conditions.