School of Chemical & Physical Sciences From nuclear materials to nuclear clocks – some highlights of 36 years of materials modelling Robert A Jackson School of Chemical & Physical Sciences Keele University Keele, Staffs ST5 5BG, UK r.a.jackson@keele.ac.uk @robajackson http://www.slideshare.net/robajackson

Plan of talk Where it all started – modelling nuclear materials An excursion into zeolites A distraction of molecular ionics Optical materials Lithium niobate The renaissance of nuclear materials modelling Acknowledgements and reminiscences #CRAC index 27 (or 32?) Advances in computational and experimental studies of solids, 10-12 April 2017

Richard’s group at UCL, 1983 Photo shows: Back: Alan, Lee Moroney, Frank Beech, Richard, Alastair, Clive Freeman, Andy Murray. Front: François Theobald, Simon Tomlinson, Mick Sanders, Glen Lewis, Rebecca Royle, Andy Hope Location: Exmouth Arms – still there (and recently refurbished), but threatened by HS2 developments. Advances in computational and experimental studies of solids, 10-12 April 2017

Fission gas in UO2 My first project with Richard – using his UO2 potential and electron-gas potentials to represent Xe-O interactions. This was followed by development of a new potential, with John Harding and Andy Murray. Advances in computational and experimental studies of solids, 10-12 April 2017

A new UO2 potential This new potential was fitted to lattice parameter measurements, and included calculations of the entropy of formation of defects using John Harding’s SHEOL code. Advances in computational and experimental studies of solids, 10-12 April 2017

A change of direction – Keele & zeolites In 1986 I joined Richard’s group at Keele. A 2-year contract that turned into a career! I shared an office with the gentlemen below (Robin and Rajappan Vetrivel). Photos from 1987 Advances in computational and experimental studies of solids, 10-12 April 2017

Modelling zeolites Earlier work by Richard, Steve Parker, Mick Sanders and Maurice Leslie had led to potentials initially for SiO2 which were later applied to zeolites. The project was funded by Shell, working with Rutger van Santen. This project produced a paper which has been used by many people starting work on zeolites (and is my most cited): Advances in computational and experimental studies of solids, 10-12 April 2017

Computer simulation studies of zeolite structure Advances in computational and experimental studies of solids, 10-12 April 2017

Molecular ionic materials Another change of direction led to work on molecular ionic materials, with Kevin Roberts and David Price. Calcium carbonate has been much studied since, but one of the earlier papers was the one shown top right. The other paper describes potential derivation for perchlorates and an excursion into morphological modelling (next slide). Advances in computational and experimental studies of solids, 10-12 April 2017

Calculation of morphologies: surface and attachment energies. Advances in computational and experimental studies of solids, 10-12 April 2017

Optical materials My interest in optical materials started through a collaboration with Mário Valerio. This involved modelling dopants in mixed metal fluorides and predicting their location and optical behaviour. As the photo shows, discussion is important! Advances in computational and experimental studies of solids, 10-12 April 2017

Lithium niobate Lithium niobate had earlier been modelled by Richard, Simon Tomlinson and Hans Donnerberg, but the enduring interest in the material led to the derivation of a new potential. Papers from then and now are shown: Advances in computational and experimental studies of solids, 10-12 April 2017

A renaissance of nuclear fuels modelling My return to modelling nuclear fuels was around 2010, and coincided with a new collaboration with Mark Read. Using his potential fitting methodology, we derived new potentials for UO2 and subsequently, PuO2. Advances in computational and experimental studies of solids, 10-12 April 2017

We remember and miss these former group members and collaborators Alan Gorman Behnam Vessal Patrick Jacobs Elizabeth Colbourn Marshall Stoneham Erasmus Rammutla Khomotso Kganyago (Reggie) Mark Rodger Advances in computational and experimental studies of solids, 10-12 April 2017

And finally, time for some royal outreach… Photo by David Coombes Advances in computational and experimental studies of solids, 10-12 April 2017

Acknowledgements Thanks above all go to Richard, who got me started on my career, and has helped and advised me ever since. For the meeting, I would like to thank Tina, my contact at Cosener’s House, and Josie Goodall, who has helped me with administration. Finally, thank you all for attending! Advances in computational and experimental studies of solids, 10-12 April 2017