A computationally efficient quasi-harmonic study of ice polymorphs using the FFLUX force field
2025

Study of Ice Polymorphs Using the FFLUX Force Field

publication Evidence: moderate

Author Information

Author(s): Alexandra Pák, Matthew L. Brown, Paul L. A. Popelier

Primary Institution: University of Manchester

Hypothesis

Can the FFLUX force field efficiently calculate Gibbs free energies of ice polymorphs with reduced computational cost?

Conclusion

The FFLUX force field can calculate Gibbs free energies of ice polymorphs efficiently, but it struggles with the accuracy of relative stability rankings.

Supporting Evidence

  • FFLUX calculations are estimated to be 103–105 times faster than traditional DFT methods.
  • FFLUX reproduces experimental lattice parameters within 5%.
  • FFLUX incorrectly identified ice II as unstable, leading to the discovery of a new phase, II′.

Takeaway

This study looks at different types of ice and how we can use a special computer model to understand their properties better and faster.

Methodology

The study used the FFLUX force field to calculate Gibbs free energies of ice polymorphs through quasi-harmonic lattice dynamics calculations.

Limitations

The parametrized non-bonded potentials negatively affect the accuracy of the model, leading to large errors in the free energies calculated.

Digital Object Identifier (DOI)

10.1107/S2053273324010921

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