I prefer writing to speaking, but from time to time the latter is necessary. When I quite young, I joined a speech and drama club that included mime and poetry. I still remember being on stage at Father Mathew Hall (Dublin City) for a competition. There was no fear in an eight year old me.

That confidence was lost, and I clearly recall my final year presentation as a Chemistry undergraduate, with quivering voice and shaking hands. As a postgraduate, my first conference presentation was at Oxford. I made the mistake of sitting at the back of the room. It was a long and terrifying walk to the front of the auditorium, but I survived. I knew that first talk by heart (and probably sounded like a nervous robot).

Of course presentations play an important role in science, so I had to work at it. I read quite a few books on public speaking (from the dreaded self-help section of the book shop). There were some good general speaker tips:

• Visit the room early to get used to the presenter view
• Speak slowly and clearly
• Face the audience as much as possible
• Try not to walk around
• Avoid repetitive words or hand movements
• Always bring your own pointer and laptop
• Practice

and some general content tips:

• Tell a story: a beginning, middle, and end
• Have a single message per slide
• Know your audience (tailor the content for them)
• Use the minimal amount of text
• Simple is best (no fancy transitions)
• Large fonts (for the people at the back)

No matter how much you read, it can be difficult to overcome your default behavior and reactions in the moment. Standing in front of your peers is not easy - I have seen senior professors from top universities being as nervous as first year students. I find it depends as much on the event itself (room layout and setup, audience interest and atmosphere). The worst case scenario is a half empty room of disinterested people with a microphone that keeps clipping. So I find that even with a similar set of slides, a talk can be a disaster, okay or great.

Despite all of the words above, it really comes down to the results. If you have something interesting to present, it doesn't matter how you do it. One of the most memorable talks I have seen is a student who stood up and delivered a 15 minute monologue (no slides or data). There are no rules.

There have been discussions regarding hysteresis in the performance of hybrid halide perovskite solar cells since the MRS Fall Meeting in 2013 (a brave presentation from the group of Mike McGehee and supplementary slides from the presentation of Henry Snaith). Since then, there has been a flurry of papers reporting and attempting to characterise the behaviour (see a news piece in Chemistry World this week).

A related phenomenon is the low frequency dielectric dispersion of these materials (mentioned in my recent stream of consciousness), where large polarisation features emerge due to build up of charge (e.g. see the Maxwell-Wagner effect).

This effect reminded me of some arugments in the literature several years ago regarding the characterisation of ferroelectric materials (from Bananas go Paralectric to Ferroelectrics go Bananas). The response observed for a banana is remarkably similar to the "giant dielectric effect" reported for the (inedible) hybrid halide perovskites. Quite a chunk of literature can be rationalised through this anology: "With simple experiments, the response of a banana to electric fields is revealed as characteristic for an inhomogeneous paraelectric ion conductor."

Food for thought...

Having time to read was one of the few perks of feeling ill over the Christmas holidays. I had a chance to finish the 1964 classic text by J. M. Ziman, Principles of the Theory of Solids. He writes with a certain eloquence and authority that you don’t often find in physical science. It is not a text for true beginners, but addresses many fundamental concepts in condensed-matter physics with a unique perspective and a clear narrative.

For research, 2014 has been an extremely fun year. Many new projects that went in unexpected directions, keeping things fresh and interesting. My research group composition has been changing too (Out: Lee to Kytoto, Davide to Oxford and Rachel to Queen Mary; In: Suzy from York, Ruoxi from Fudan, Katrine from Aarhus), which alters the dynamic. There is no such thing as a quiet or normal week.

Publications from 2014:

• Automated procedure to determine the thermodynamic stability of a material and the range of chemical potentials necessary for its formation relative to competing phases and compounds
• Electronic structure and band alignment of zinc nitride, Zn3N2 (OA)
• From kesterite to stannite photovoltaics: Stability and band gaps of the Cu2(Zn,Fe)SnS4 alloy (OA)
• N incorporation and associated localized vibrational modes in GaSb
• Prediction of Electron Energies in Metal Oxides (OA)
• Three-electron two-centred bonds and the stabilisation of cationic sulfur radicals (OA)
• Crystal electron binding energy and surface work function control of tin dioxide
• Defect chemistry of Ti and Fe impurities and aggregates in Al2O3 (OA)
• Computational screening of structural and compositional factors for electrically conductive coordination polymers (OA)
• Relativistic quasiparticle self-consistent electronic structure of hybrid halide perovskite photovoltaic absorbers
• Ultra-thin oxide films for band engineering: design principles and numerical experiments
• Ab initio thermodynamic model of Cu2ZnSnS4 (OA)
• Atomistic Origins of High-Performance in Hybrid Halide Perovskite Solar Cells (OA)
• Thermal physics of the lead chalcogenides PbS, PbSe, and PbTe from first principles
• Origin of deep subgap states in amorphous indium gallium zinc oxide: Chemically disordered coordination of oxygen
• Design of I2−II−IV−VI4 Semiconductors through Element Substitution: The Thermodynamic Stability Limit and Chemical Trend
• Electronic Chemical Potentials of Porous Metal−Organic Frameworks (OA)
• Ellipsometric characterization and density-functional theory analysis of anisotropic optical properties of single-crystal SnS
• Molecular ferroelectric contributions to anomalous hysteresis in hybrid perovskite solar cells (OA)
• Identification of critical stacking faults in thin-film CdTe solar cells
• Stacking-dependent energetics and electronic structure of ultrathin polymorphic V2VI3 topological insulator nanofilms
• Ligand design for long-range magnetic order in metal–organic frameworks (OA)
• Transferable Force Field for Metal−Organic Frameworks from First-Principles: BTW-FF (OA)
• Tunable Trimers: Using Temperature and Pressure to Control Luminescent Emission in Gold(I) Pyrazolate-Based Trimers (OA)
• Electronic Structure Modulation of Metal−Organic Frameworks for Hybrid Devices (OA)

We have done better for fully open access (OA) publications this year, but still room for improvement. Generally, we don't pay for gold open access with the American Physical Society (e.g. Physical Review B or Physical Review Letters) because they have the most generous policy for hosting on preprint servers, personal websites and institutional databases.

[fade to black and white] I remember hunting down a series of 1950s papers on sterochemical lone pairs by L. E. Orgel at the start of my PhD. There was the wonderful satisfaction of finding the right volume of the journal, photocopying the paper, and then curling up in the corner of the library basement to read it. If I started this year, a quick web search just sends me to the right place.

Immediate access to information is useful, but it makes it increasingly difficult to navigate the expanding literature. Even in my general area of computational materials chemistry, there are too many journals, papers and authors to keep track of. My current workflow involves the following web services:

• Google Scholar. The commercial Web of Science and Scopus search engines are quickly becoming redundant. Google is faster and more effective. There are some nice features such as direct export to BibTeX, and access to pdfs that you may not have subscriptions to (e.g. stored on personal websites or online databases). There is also a surprisingly accurate alert system, which gives you recommended reading based on the papers you have published and cited.

• Mendeley. On one hand, Mendeley is useful for sharing papers. I use it for maintaining a list of publications in the emerging field of hybrid perovskites, for keeping track of our journal club, and an essential reading list for new students. The desktop client is also very useful for synching pdfs across machines (including notes and annotations), and for maintaining a bibliography for LaTeX or Word documents. The cite-as-you-write feature has now made Endnote  redundant (which has always been a clunky and error prone piece of software). Mendeley is particularly smart at importing missing database entries when you edit a collaborator's document.
• Old Reader. Since the early death of Google Reader, I tried out many options for tracking RSS feeds from journals in my field. Eventually, I settled with the Old Reader. As the name suggests it maintains the functionality of Google Reader. It is fast and displays TOC art quite nicely. The alternative is weekly alert emails from journals, but I enjoy my morning coffee browsing through the new articles of the day (caffeine and new science are equally addictive).

The absence of regular postings isn't due to a lack of things to say, but a lack of free time.

Time management is my biggest challenge these days. I have a dozen wonderful group members, doing great research. It is a full time job just to keep up with them, and then I have to find time for my own research, presentations and the bane of all academics, bureaucracy. I am not complaining, I have never enjoyed science as much as I do now.

My research group is now focused on three areas: photovoltaic materials; metal-organic frameworks, and metastable states. Some topics, such as hybrid halide perovskites, are bridging all three themes due to the complexity of their chemistry and physics. A major driving force for our current work is temperature dependent properties (see Jonathan Skelton's pro-tip guide for Phonopy) and disorder. When I have some free time, I can be found reading some dusty statistical mechanics (one essential read) or thermal physics texts.

Time now to prepare for another trip to South Korea. This time there is a workshop between Yonsei University and the University of Bath to expand the range and depth of collaborations, followed by an exciting Royal Society collaboration with the Korean Institutes for Basic Science (to be held at Seoul National University). No doubt the next few days will pose exciting adventures in culture, food and functional materials.