Can We Predict the Pressure Induced Phase Transition of Urea? Application of Quantum Molecular Dynamics.

ABSTRACT: Crystalline urea undergoes polymorphic phase transition induced by high pressure. Form I, which is the most stable form at normal conditions and Form IV, which is the most stable form at 3.10 GPa, not only crystallize in various crystal systems but also differ significantly in the unit cell dimensions. The aim of this study was to determine if it is possible to predict polymorphic phase transitions by optimizing Form I at high pressure and Form IV at low pressure. To achieve this aim, a large number of periodic density functional theory (DFT) calculations were performed using CASTEP. After geometry optimization of Form IV at 0 GPa Form I was obtained, performing energy minimization of Form I at high pressure did not result in Form IV. However, employing quantum molecular isothermal-isobari

SUBMITTER: Mazurek A 

PROVIDER: S-EPMC7180756 | biostudies-literature | 2020 Mar

REPOSITORIES: biostudies-literature