Potassium dihydrogen phosphate (KH2PO4, abbreviated as KDP) is the blueprint for a set of hydrogen-bonded ferroelectrics. Irrespective of KDP's comparatively simple structure, it has attracted the interest of many theoretical and experimental researchers because of its fascinating properties associated with this hydrogen bond system that features a significant isotope effect. Its unique piezoelectric, ferroelectric, and electro-optic properties are of great importance. Due to their piezoelectric effect, KDP crystals have wide applications in conventional and nuclear weapon fuse, accelerometers, sonar generators antisubmarine detectors, and underwater acoustic transducers. In addition, KDP crystals have also been widely used as a photoelectric material in laser communication. Thus, KDP crystals are an important material across a range of applications in both consumer and high technology fields.

Recent experimental studies have shown some interesting nucleation and crystal growth behavior in supersaturated KDP solutions. Growth of microfibers indicating quasi-one-dimensional growth has been observed and it is shown that one of these microstructures formed has the same molecular structure and symmetry identical to the type lV monoclinic crystal structure that was previously found to exist only under high pressure. In addition, the microstructures formed which are centrosymmetric can produce efficient second-harmonic generation. Although the underlying molecular mechanism responsible for the quasi-one-dimensional growth has not yet been discovered, changes in solution structure have been reported, and pre nucleation clusters and multistep nucleation pathways have been proposed. The ability to grow such microstructures opens the potential application of KDP in micro photonics. Experimental studies to date indicate that a thorough study of the solution microstructure of KDP is essential to understand the underlying mechanism of nucleation and crystal growth from an aqueous solution. It is noteworthy that there are no previous molecular simulation studies reporting the observation of KDP crystal growth or nucleation. Our objective is to reveal how solution structure may impact crystallization behavior while uncovering the fundamental features of the ordering process underlying crystal formation from KDP solution. In this presentation, we will examine several different force-field models for aqueous KDP solutions and will report results for their solution structure. Through comparison with experimental results, we will identify the most suitable model. The models will also be tested for their ability to reproduce the experimental crystal structure. Analysis of ion clusters that appear in supersaturated solutions will also be reported.