PhD project: Crystal structure prediction from free energies

Project description

It is a remarkable fact that there is no known way to determine what the crystal structure of a material should be at given temperature and pressure.  The best that can be done is to find candidate structures and compare them.  

Massive advances in this area have been made in the last ten years using massive computation of quantum energies, based on density functional theory, to carry out exhaustive searches of structures at zero temperature, and without nuclear quantum effects.     The physics of entropic uncertainty and quantum uncertainty are very different, but the practicalities of calculation  are similar - the energy of many possible configurations must be sampled and combined in an appropriate way.

In this project, you will work with new methods based on Monte Carlo simulation to include both finite temperature an nuclear quantum effects in determining phase stability.  The ideas are based around Path-Integral and Lattice-Switch Monte Carlo and involve heavy supercomputation.

A related problem is how these methods can be constrained by experimental data.  In many cases, particularly for light elements at pressure, the only available data is spectroscopy which is insufficient to determine the structure precisely, but can definitively rule out some candidates.  Part of the project will be to work closely with experimentalists in CSEC to interpret their data, with particular emphasis on hydrogen and hydrogen-rich compounds, which have recently been breaking records for high-temperature superconductivity.

This project is also available with advanced training in our new CDT: Information about that is here,

Project supervisor

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