Newsletter 107 - October 2011 - (pdf - 0.6 MB) - Psi-k

3 General Job Announcements
Postdoc Position: First-Principles Simulations and Modeling of
Phonon Linewidths in Thermoelectric Materials at Oak Ridge
National Laboratory, USA
Project description:
The goal of this project is to gain knowledge about phonon linewidths (inverse of lifetimes),
and their systematic dependence on temperature, composition, or the underlying
electronic structure, to predict their impact on thermoelectric efficiency [1,2,3,4,5]. The
project involves collaboration between leading experimentalists, ab-initio theorists, and
computer scientists at ORNL. The research will involve performing detailed calculations
of phonon energies and linewidths (using first-principles as well as force-field methods),
and benchmarking against experimental measurements. The tasks will include writing
software to fit experimental data with parameterized models, and perform numerical optimization
of phonon lifetimes. The software will be implemented on the high-performance
computers at ORNL (including hybrid architecture based on General Purpose Graphical
Processing Unit) to optimize our phonon dynamics models, and directly fit the experimental
datasets. The convolution of phonon simulations with the response function of
neutron scattering spectrometers at the Spallation Neutron Source will produce realistic
simulated datasets, directly comparable with experiments. The outcome of this research
will enable benchmarking microscopic theories of thermal conductivity, and develop more
efficient thermoelectric materials. This research will leverage the world-class computing
and neutron scattering resources of ORNL.
Qualifications:
Candidates with a recent Ph.D. in Physics, Materials Science, Chemistry, or related fields
will be considered. Expertise with first-principles simulations (density functional theory),
and in particular phonon simulations (with linear response or direct method), is a requirement
for this position. Experience with molecular dynamics simulations, anharmonicity
calculations, many-body techniques, and numerical optimization will be helpful. Good
programming skills with modern computer languages (C++, Python) will be a strong advantage.
Strong written and oral communication skills and the desire to work in a team
environment on scientifically challenging problems are required. The successful candidate
will conduct research at Oak Ridge National Laboratory, and will make use of computing
facilities at ORNL. Applicants cannot have received their Ph.D. more than five years prior
to the date of application and must complete all degree requirements before starting their
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