Applications are invited for a Postdoctoral Researcher position at CRANN Research Institute, Trinity College Dublin, The University of Dublin, Ireland, and associated with AMBER, the Science Foundation Ireland Research Centre for Advanced Materials and BioEngineering Research. The successful candidate will join the Condensed Matter Theory Group lead by Prof. David O’Regan.

The Researcher will play a central role in a new Science Foundation Ireland funded research project in partnership with a major technology company, with the objective of establishing the regime of reliability and computational viability of first-principles DFT+U+J for non-magnetic oxides.

The appointment will be made for 1 year, with a gross annual salary in the region of EUR 42,559 (plus 20% employer pension and 11.05% employer social insurance contributions), depending on the successful candidate’s level of prior experience. Further extension may be possible, depending on the continuation of funding, the appointee’s performance, as well as the project’s evolving scientific priorities. A start date as early as 1st Sept 2020 may be possible.

Background
The band gap of insulators is a key material property, but is notoriously difficult to predict accurately. For transition-metal oxides, correcting approximate DFT with Hubbard U terms offers an inexpensive solution. This is made first-principles by calculating the necessary U parameters. However, for many oxides, the spread of literature gap values is remains large, and predicted gaps are often disappointing when magnetism is absent.

We have recently found that, starting from an inexpensive functional, calculating the corresponding U directly and letting the exchange correction parameter J come as a free by-product, we calculate rather accurate band gaps for two different titania crystal structures [1]. This procedure combines ‘minimum-tracking’ linear-response formulae [2] for U and J, with a streamlined +U+J functional [3].

The aim of this project is to now establish the wider regime of reliability and computational viability of this approach for non-magnetic oxides, by testing it on properties of interest in a range of representative systems, against appropriate benchmarks.

The successful candidate will:
• Perform a comprehensive literature review and tabulate the experimental and theoretical electronic structure properties of selected oxides.                               

• Implement and test the necessary expectation values for minimum-tracking linear-response in a plane-wave pseudopotential DFT code.
• For selected oxides, benchmark the method for ionic geometry, band-structure, and vacancy formation energies, against e.g. hybrid functionals.
• Take initiative to develop their own career and competences within the project framework, by availing of research and career development training available at Trinity; by travelling overseas (when conditions allow) and presenting their work to the highest standards at relevant scientific events; disseminating their developments, participating in relevant outreach activities (for which support and training may be available), and possibly assisting in the mentorship of students and their research projects.

Requirements
• A Ph.D. (or recently submitted Ph.D. thesis awaiting examination) involving research in first-principles electronic structure simulation and method development, ideally with hands-on experience in local orbital methods within plane-wave pseudopotential DFT codes.
• Proficiency in the use of high-performance computing, including shell scripting, MPI programming in Fortran, and proven experience in high-quality graphics production.
• Excellent spoken and written English, a self-starting approach to reporting and writing, a keen attention to detail, and impeccable scientific integrity, record keeping, and standards.
• Courtesy and respect for all colleagues, collaborators and students, irrespective of their disability, gender identity, sexuality, age, race, civil status, family status, nationality, ethnicity, cultural or socio-economic background.
• The desire to advance electronic structure theory at both a local community and global level, and to pro-actively develop your profile and career.

How to apply
All communication concerning this opportunity should be sent to [email protected] with subject line ‘Postdoctoral Researcher in First-principles DFT+U+J’. Applications must take the form of one single pdf document only, comprising:
i. A curriculum vitae / résumé including a complete list of publications and relevant outputs, academic degree results and/or rankings, and any awards, distinctions or relevant experience.
ii. A cover letter explaining your motivation for applying, and you career goals and plans.
iii. A sample of your own scientific writing, e.g. a paper or research thesis chapter.
iv. Contact details of three referees who are informed, willing, and available for contact in regards to your application.
The position will remain open until a suitable candidate is identified. A first round of application assessment will be carried out after a cut-off of Monday 17st August.

Equal Opportunities Policy
Trinity is an equal opportunities employer and is committed to employment policies, procedures and practices which do not discriminate on grounds such as gender, civil status, family status, age, disability, race, religious belief, sexual orientation or membership of the travelling community. On that basis we encourage and welcome talented people from all backgrounds to join our staff community.

References
[1] O. K. Orhan and D. D. O’Regan, Phys. Rev. B 101, 245137 (2020).
[2] E. B. Linscott, et al., Phys. Rev. B 98, 235157 (2018).
[3] B. Himmetoglu, et al., Phys. Rev. B84, 115108 (2011).