Professor Sally (Sarah) Price

Sally trained at the University of Cambridge, completing her PhD on model intermolecular potentials for diatomic molecules, mainly (H2)2. Apart from an overseas postdoc in Chicago, Sally has worked on deriving models for the forces between polyatomic molecules from the theory of intermolecular forces and electronic structure calculations, for all of her scientific career.

“The molecules have got bigger, and the applications have moved from the gas phase to condensed phases”.

This came in two steps, the first as Sally moved from Royal Society University Research Fellowship at Cambridge, to UCL.  Here she wrote a grant proposal to develop a code to implement anisotropic atom-atom intermolecular potentials for modelling organic crystal structures (now DMACRYS).  Atomic multipoles, derived from the molecular charge distribution, represent the directionality of hydrogen bonding and pi-pi interactions sufficiently well that this code proved “good enough” for worthwhile organic crystal structure prediction (CSP), at least for rigid molecules. Sally soon enlisted undergraduate project students to run CSP calculations and carried out experimental crystallisations on the same molecule with her colleague Derek Tocher.  This led to the second and biggest step in Sally’s career – leading a large project (Control and Prediction of the Organic Solid State), combining experimental and computational work on polymorphism over many UK sites, including working alongside Alastair Florence who was responsible for developing an early crystallisation robot in Strathclyde.

The last two decades have seen a huge growth in the organic solid-state community who have to be interested in predicting polymorphism, as well as advances in experimental characterisation techniques and what is possible computationally.

Collaborative work is key to Sally’s research.  She tells us “It has been fun working with people from a large range of disciplines, from computer to pharmaceutical scientists. The CSP infrastructure that we use relies on CSP algorithms developed by Costas Pantelides and Claire Adijman at Imperial which incorporate DMACRYS, and also uses tools developed by the Cambridge Crystallographic Data Centre.  We also use CASTEP, as well as developing the use of more accurate non-empirical force-fields.   Different molecules have presented different challenges, and industrial collaborations have proved very fruitful.

I most enjoy teamwork; putting together pieces of the puzzle to make a coherent molecular level picture.

I have been fortunate to have received inspiration, encouragement and practical help from a wide range of people, most of whom have continued working with me into their retirement, including my PhD supervisor Anthony Stone,  Richard Catlow, Maurice Leslie (the main developer of DMACRYS), and Bob Lancaster who helped with the experimental work at UCL after retiring from GSK.  Age has its advantages when most projects take far longer than expected because the molecules do not behave according to our over-simplified theories”.