Tag: academic life

E-MRS Spring meeting 2023

In march 2019, Belgium went into COVID-lock down while I attended the yearly diamond conference (SBDD25). Since then, I have been in a bit of a conference lock down myself as well. By visiting the 2023 spring meeting of E-MRS, this lock down has been lifted for international conferences (outside Belgium). Inside Belgium, there was already the DFT-2022 in Brussels, where I was also part of the National Scientific Committee, and of course SBDD26 & SBDD27, which as a diamond researcher you can not miss.

Coming back to Strassbourg for E-MRS brings back some memories, and generated some nice new ones. This year there was a nice Symposium called “Computations for materials – discovery, design and the role of data“[program] which got my full attention. During the first session on AI-accelerated Materials discovery, I had the pleasure to present some of my own work on the Machine Learning of small data sets (cf. papers on the average model, and UV-curable inks). The symposium was nicely coinciding with much of my interest, and showed two (not unexpected, and maybe symposium biased) trends:

  1.  There is an important evolution toward lab-automation and use of robotics (people don’t want to manually build dozens of battery cells or perform hundreds of repetitive synthesis experiments for materials optimization. This shows the future materials scientist, be it a chemist, physicist or engineer will have to become a robotics and/or programming expert as well. This only strengthens me in my vision for our materiomics [NL] students at UHasselt. These skills will be essential for their future scientific career development.
  2. Machine Learning and Artificial Intelligence will play an important role in future materials design. However, we need a better understanding of what we are doing, and not just use any method and accept it as “excellent” because the R² value is high. For now, we can still get away with the latter, but this will not last much longer. It will become more important to have a simple but interpretable model, rather than a complex (over-fitting) Deep Learning Neural Network without understanding of the underlying physics and chemistry. Also here we will have to put in some effort within the materiomics program.


So after an interesting International conference, and making some new contacts…it is time to return home, four more courses need to be prepared from scratch for coming academic year.

SBDD 25 (aka the COVID19 edition)

Last Wednesday, the 25th edition of the Hasselt Diamond workshop started. The central topic of this celebratory edition was focused on surfaces, perfectly suited to present some of my more recent diamond based work.[1][2] Just as the previous years, the program was packed with interesting talks on anything diamond. Phosphorous doped diamond seemed to be the “new thing” this year, but I could be biased, as I was speaking on phosphorous adsorption myself. Due to a cancellation, I found myself being asked on Monday afternoon to present my work as a talk 😎 , on Wednesday morning 😯 . Because I had been a bit too ambitious in my conference abstract, this talk ended up being nicely complementary to my poster.

Poster SBDD 25 conference, Hasselt 2020

Unfortunately, this celebratory edition also fell victim to the COVID-19 crisis. In addition to being the most popular conversation topic—a close second to diamond research—, it also had a very real impact on the conference itself. The COVID-19 crisis resulted in a drop of attendance from 238 people in 2019 to 143 this year.  In addition, the quickly changing situation worldwide lead to last minute cancellations due to travel restrictions. On Thursday evening, the conference site went into lock down. Furthermore, that evening, the Belgian federal government also decided that schools and higher education should be closed, as well as pubs and restaurants, until April 3rd. There was also the urgent request for people to work from home as much as possible. (Consider this a good example of acting NOW aimed at saving people.)

Consider this computational scientist in lock down in his home lab until further notice.

Casting Keynotes: The Virtual Lab

Last Tuesday? I had the pleasure of competing in the casting keynotes competition of the TEDx UHasselt chapter. An evening filled with interesting talks on subjects ranging from the FAIR principles of open-data (by Liebet Peeters)  to the duty not stay silent in the face of “bad ideas” and leading a life of purpose. An interesting presentation was the one by Ann Bessemans on visual prosody to improve reading skills in young children as well as reading experience, more specifically the transfer of non-literal-content, for non-native speakers. There was also time for some humor, with the dangerous life of Tim Biesmans, who suffers from peanut-allergies. For him, death lurks around every corner, even in a first-date’s kiss. During my talk, I traced the evolution of computational research as the third paradigm of scientific discovery, showing you can find computational research in every field, and why it is evolving at its break-neck speed.

During the event, both the public and a jury voted on the best presentation, which would then have to present at the TEDx UHasselt in 2020.

And the Winner is …drum roll… Danny Vanpoucke!

So this story will continue during the 2020 TEDx event at UHasselt, and I hope to see you there 🙂

Casting Keynotes

top: Full action shots of my presentation. Moore’s Law as driving force behind computational research, and pondering the meaning of Artificial Intelligence. Bottom: Yes, I won 🙂


VSC-users day 2019

It is becoming an interesting yearly occurrence: the VSC user day. During this 5th edition, HPC users of the various Flemish universities gather together at the Belgian Royal Academy of Science (KVAB) to present their state-of-the-art work using the Flemish Tier-1 and Tier-2 supercomputers. This is done during a poster-presentation session. This year, I presented my work with regard to vibrational spectra in solids and periodic systems. In contrast to molecules, vibrational spectra in solids are rarely investigated at the quantum mechanical level due to their high cost. I show that imaginary modes are not necessarily a result of structural instabilities, and I present a method for identifying the vibrational spectrum of a defect.

Poster for the VSC user day 2019.

In addition, international speakers discuss recent (r)evolutions in High Performance Computing, and during workshops, the participants are introduced in new topics such as GPU-computing, parallelization, and the VSC Cloud and data platform. The possibilities of GPU were presented by Ehsan, of the VSC, showing extreme speedups of 10x to 100x, strongly depending on the application, the graphics card. It is interesting to see that simple CUDA prama’s can be used to obtain such effects…maybe I should have a go at them for the Hirshfeld and phonon parts of my HIVE code…if they can deal with quadruple precision, and very large arrays. During the presentation of Joost Vandevondele (ETH Zürich) we learned what the future holds with regard to next generation HPC machines. As increasing speed becomes harder and harder to obtain, people are again looking into dedicated hardware systems, a situation akin to the founding days of HPC. Whether this is a situation we should applaud remains to be seen, as it means that we are moving back to codes written for specific machines. This decrease in portability will probably be alleviated by high level scripting languages (such as python), which at the same time result in a significant loss of the initial gain. (Think of the framework approach to modern programming which leads to trivial applications requiring HPC resources to start.)

In addition, this year the HPC-team of the TIER-1 machine is present for a panel discussion, presenting the future of the infrastructure. The machine nearly doubled in size which is great news. Let us hope that in addition for financing hardware, there is also a significant budget considered for a serious extension of a dedicated HPC support team. Running a Tier-1 machine is not something one does as a side-project, but which requires a constant vigilance of a dedicated team to deal with software updates, resulting compatibility issues, conflicting scripts and just hardware and software running haywire because they can.

With this hope, I look toward the future. A future where computational research is steadily are every quickly is becoming common place in the fabric om academic endeavors.

Universiteit Van Vlaanderen

A bit over 1 month ago, I told you about my adventure at the film studio of “de Universiteit Van Vlaanderen“. Today is the day the movie is officially released. You can find it at the website of de Universiteit Van Vlaanderen: Video. The video is in Dutch as this is a science-communication platform aimed at the local population, presenting the expertise available at our local universities.


In addition to this video, I was asked by Knack magazine to write a piece on the topic presented. As computational research is my central business I wrote a piece on the subject introducing the general public to the topic. The piece can be read here (in Dutch).

And of course, before I forget, this weekend there was also the half-yearly daylight saving exercise with our clocks.[and in Dutch]


SBDD XXIV: Diamond workshop

The participants to SBDD XXIV of 2019.  (courtesy of Jorne Raymakers, SBDD XXIV secretary) 


Last week the 24th edition of the Hasselt diamond workshop took place (this year chaired by Christoph Becher). It’s already the fourth time, since 2016, I have attended this conference, and each year it is a joy to meet up with the familiar faces of the diamond research field. The program was packed, as usual. And this year the NV-center was again predominantly present as the all-purpose quantum defect in diamond. I keep being amazed at how much it is used (although it has a rather low efficiency) and also about how many open question remain with regard to its incorporation during growth. With a little luck, you may read more about this in the future, as it is one of a few dozen ideas and questions I want to investigate.

A very interesting talk was given by Yamaguchi Takahide, who is combining hexagonal-BN and H-terminated diamond for high performance electronic devices. In such a device the h-BN leads to the formation of a 2D hole-gas at the interface (i.e., surface transfer doping), making it interesting for low dimensional applications. (And it of course hints at the opportunities available with other 2D materials.) The most interesting fact, as well as the most mind-boggling to my opinion, was the fact that there was no clear picture of the atomic structure of the interface. But that is probably just me. For experiments, nature tends to make sure everything is alright, while we lowly computational materials artificers need to know where each and every atom belongs. I’ll have to make some time to find out.

A second extremely interesting presentation was given by Anke Krueger (who will be the chair of the 25th edition of SBDD next year), showing of her groups skill at creating fluorine terminated diamond…without getting themselves killed. The surface termination of diamond with fluorine comes with many different hazards, going from mere poisoning, to fire and explosions. The take-home message: “kids don’t try this at home”. Despite all this risky business, a surface coverage of up to 85% was achieved, providing a new surface termination for diamond, with a much stronger trapping of negative charges near the surface, ideal for forming negatively charged NV centers.

On the last day, Rozita Rouzbahani presented our collaboration on the growth of B doped diamond. She studied the impact of growth conditions on the B concentration and growth speed of B doped diamond surfaces. My computational results corroborate her results and presents the atomic scale mechanism resulting in an increased doping concentration upon increased growth speed. I am looking forward to the submission of this nice piece of research.

And now, we wait another year for the next edition of SBDD, the celebratory 25th edition with a focus on diamond surfaces.

Universiteit Van Vlaanderen: Will we be able to design new materials using our smartphone in the future?

Yesterday, I had the pleasure of giving a lecture for the Universiteit van Vlaanderen, a science communication platform where Flemish academics are asked to answer “a question related to their research“. This question is aimed to be highly clickable and very much simplified. The lecture on the other hand is aimed at a general lay public.

I build my lecture around the topic of materials simulations at the atomic scale. This task ended up being rather challenging, as my computational research has very little direct overlap with the everyday life of the average person. I deal with supercomputers (which these days tend to be bench-marked in terms of smartphone power) and the quantum mechanical simulation of materials at the atomic scale, two other topics which may ring a bell…but only as abstract topics people may have heard of.

Therefor, I crafted a story taking people on a fast ride down the rabbit hole of my work. Starting from the almost divine power of the computational materials scientist over his theoretical sample, over the reality of nano-scale materials in our day-to-day lives, past the relative size of atoms and through the game nature of simulations and the salvation of computational research by grace of Moore’s Law…to the conclusion that in 25 years, we may be designing the next generation of CPU materials on our smartphone instead of a TIER-1 supercomputer. …did I say we went down the rabbit hole?

The television experience itself was very exhilarating for me. Although my actual lecture took only 15 minutes, the entire event took almost a full day. Starting with preparations and a trial run in the afternoon (for me and my 4 colleagues) followed by make-up (to make me look pretty on television 🙂 … or just to reduce my reflectance). In the evening we had a group diner meeting the people who would be in charge of the technical aspects and entertainment of the public. And then it was 19h30. Tensions started to grow. The public entered the studio, and the show was ready to start. Before each lecture, there was a short interview to test sound and light, and introduce us to the public. As the middle presenter, I had the comfortable position not to be the first, so I could get an idea of how things went for my colleagues, and not to be the last, which can really be destructive on your nerves.

At 21h00, I was up…

and down the rabbit hole we went. 



Full periodic table, with all elements presented with their relative size (if known)

Full periodic table, with all elements presented with their relative size (if known) created for the Universiteit van Vlaanderen lecture.


Newsflash: Materials of the Future

This summer, I had the pleasure of being interviewed by Kim Verhaeghe, a journalist of the EOS magazine, on the topic of “materials of the future“. Materials which are currently being investigated in the lab and which in the near or distant future may have an enormous impact on our lives. While brushing up on my materials (since materials with length scales of importance beyond 1 nm are generally outside my world of accessibility), I discovered that to cover this field you would need at least an entire book just to list the “materials of the future”. Many materials deserve to be called materials of the future, because of their potential. Also depending on your background other materials may get your primary attention.

In the resulting article, Kim Verhaeghe succeeded in presenting a nice selection, and I am very happy I could contribute to the story. Introducing “the computational materials scientist” making use of supercomputers such as BrENIAC, but also new materials such as Metal-Organic Frameworks (MOF) and shedding some light on “old” materials such as diamond, graphene and carbon nanotubes.

Review of 2017

Happy New Year

2017 has come and gone. 2018 eagerly awaits getting acquainted. But first we look back one last time, trying to turn this into a old tradition. What have I done during the last year of some academic merit.

Publications: +4

Completed refereeing tasks: +8

  • The Journal of Physical Chemistry (2x)
  • Journal of Physics: Condensed Matter (3x)
  • Diamond and Related Materials (3x)

Conferences & workshops: +5 (Attended) 

  • Int. Conference on Diamond and Carbon Materials (DCM) 2017, Gothenburg, Sweden, September 3rd-7th, 2017 [oral presentation]
  • Summerschool: “Upscaling techniques for mathematical models involving multiple scales”, Hasselt, Belgium, June 26th-29th, 2017 [poster presentation]
  • VSC-user day, Brussels, Belgium, June 2nd, 2017 [poster presentation]
  • E-MRS 2017 Spring Meeting, Strasbourg, France, May 22nd-26th, 2017 [1 oral + 2 poster presentations]
  • SBDD XXII, Hasselt University, Belgium, March 8th-10th, 2017 [poster presentation]

PhD-students: +1

  • Mohammadreza Hosseini (okt.-… ,Phd student physical chemistry, Tarbiat Modares University, Teheran, Iran)

Bachelor-students: +2

Current size of HIVE:

  • 48.5K lines of program (code: 70 %)
  • ~70 files
  • 45 (command line) options

Hive-STM program:

And now, upward and onward, a new year, a fresh start.

Functional Molecular Modelling: simulating particles in excel

This semester I had several teaching assignments. I was a TA for the course biophysics for the first bachelor biomedical sciences, supervised two 3rd bachelor students physics during their first steps in the realm of computational materials science, and finally, I was responsible for half the course Functional Molecular Modelling for the first Masters Biomedical students (Bioelectronics and Nanotechnology). In this course, I introduce the the students into the basic concepts of classical molecular modelling (quantum modelling is covered by Prof. Wilfried Langenaeker). It starts with a reiteration of some basic concepts from statistics and moves on to cover the canonical ensemble. Things get more interesting with the introduction into Monte-Carlo(MC) and Molecular Dynamics(MD), where I hope to teach the students the basics needed to perform their own MC and MD simulations. This also touches the heart of what this course should cover. If I hear a title like Functional Molecular Modelling, my thoughts move directly to practical applications, developing and implementing models, and performing simulations. This becomes a bit difficult as none of the students have any programming experience or skills.

Luckily there is excel. As the basic algorithms for MC and MD are actually quite simple, this office package can be (ab)used to allow the students to perform very simple simulations. This even without the use of macro’s or any advanced features. Because Excel can also plot the data present in the cells, you immediately see how properties of the simulated system vary during the simulation, and you get direct update of all graphs every time a simulation is run.

It seems I am not the only one who is using excel for MD simulations. In 1995, Fraser and Woodcock even published a paper detailing the use of excel for performing MD simulations on a system of 100 particles. Their MD is a bit more advanced than the setup I used as it made heavy use of macro’s and needed some features to speed things up as much as possible. With the x486 66MHz computers available at that time, the simulations took of the order of hours. Which was impressive, as they served as an example of how computational speed had improved over the years, and compared to the months of supercomputer resources one of the authors had needed 25 years earlier to perform the same thing for his PhD. Nowadays the same excel simulation should only take minutes, while an actual program in Fortran or C may even execute the same thing in a matter of seconds or less.

For the classes and exercises, I made use of a simple 3-atom toy-model with Lennard-Jones interactions. The resulting simulations remain clear allowing their use for educational purposes. In case of  MC simulations, a nice added bonus is the fact that excel updates all its fields automatically when a cell is modified. As a result, all random numbers are regenerated and a new simulation can be performed by saving the excel-sheet or just modifying a not-used cell.

Monte Carlo in excel. A system of three particles on a line, with one particle fixed at 0. All particles interact through a Lennard-Jones potential. The Monte Carlo simulation shows how the particles move toward their equilibrium position.

Monte Carlo in excel. A system of three particles on a line, with one particle fixed at 0. All particles interact through a Lennard-Jones potential. The Monte Carlo simulation shows how the particles move toward their equilibrium position.

The simplicity of Newton’s equations of motion make it possible to perform simple MD simulations, and already for a three particle system, you can see how unstable the algorithm is. Implementation of the leap-frog algorithm isn’t much more complex and shows incredible the stability of this algorithm. In the plot of the total energy you can even see how the algorithm fights back to retain stability (the spikes may seem large, but the same setup with a straight forward implementation of Newton’s equation of motion quickly moves to energies of the order of 100).

Molecular dynamics in excel. A system of three particles on a line, with one particle fixed at 0. All particles interact through a Lennard-Jones potential. The Molecular dynamics simulation shows how the particles move as time evolves. Their positions are updated using the leap-frog algorithm. The extreme hard nature of the Lennard-Jones potential gives rise to the sharp spikes in the total energy. It is this last aspect which causes the straight forward implementation of Newton's equations of motion to fail.

Molecular dynamics in excel. A system of three particles on a line, with one particle fixed at 0. All particles interact through a Lennard-Jones potential. The Molecular dynamics simulation shows how the particles move as time evolves. Their positions are updated using the leap-frog algorithm. The extreme hard nature of the Lennard-Jones potential gives rise to the sharp spikes in the total energy. It is this last aspect which causes the straight forward implementation of Newton’s equations of motion to fail.