Development of a ReaxFF reactive force field for ternary phosphate-based bioactive glasses

Area of Science:

• Materials Science
• Computational Chemistry
• Biomaterials Engineering

Background:

• Phosphate-based glasses (PBGs) in the CaO-Na2O-P2O5 system are valuable biomaterials.
• Their unique dissolution properties are key to their applications.
• Simulating these materials at the atomic level is crucial for understanding their behavior.

Purpose of the Study:

• To develop a reactive force field (ReaxFF) for simulating CaO-Na2O-P2O5 based PBGs.
• To validate the developed ReaxFF potential by comparing simulated bulk structures with experimental and ab initio data.
• To lay the groundwork for future investigations into the dissolution behavior of PBGs.

Main Methods:

• Development of ReaxFF parameters using genetic algorithms.
• Training data generated from static quantum-mechanical calculations and ab initio molecular dynamics.
• Structural analysis of bulk PBGs using radial and angular distribution functions and coordination numbers.

Main Results:

• Successfully developed ReaxFF parameters for PBGs.
• Simulated bulk structures showed agreement with experimental and previous simulation data.
• Validated coordination numbers, including a phosphorus coordination number of 4.0.

Conclusions:

• The developed ReaxFF potential accurately describes the bulk structure of PBGs.
• This advancement enables future research on PBG dissolution and water interactions.
• The study provides a robust computational tool for designing advanced biomaterials.