DN-NSM 2015

Discovery of novel nanoparticles, surfaces and bulk materials

  • 9th USPEX workshop on Crystal Structure Prediction and Materials Discovery – Poitiers, 25-30 june 2015

 and its satellite

  • ES’PA 2015 – Electronic Structures: a Practical Approach. Periodic DFT for beginners hands-on tutorial- Poitiers, 22-24 june 2015

 

Outline

Prediction of the atomic structure of matter is crucial for understanding the physics and chemistry of materials [1], yet until recently was thought to be impossible [2]. A series of recent methodological developments [3-7] helped to make this problem tractable and demonstrated numerous successes. This direction of research is creating a scientific and technological revolution in our times. Among the existing methods, the most widely used one is the evolutionary algorithm USPEX [6,7], implemented in the same-name freely distributed code.(http://uspex.stonybrook.edu/uspex.html )

USPEX has outperformed all the other methods in a recent blind test of inorganic crystal structure prediction [1]. Today, the USPEX code is utilized by nearly 2200 researchers worldwide (300 in 2011) and has resulted in major advances – such as the discovery of a transparent phase of sodium, partially ionic structure of boron, and a new superhard allotrope of carbon [8-10]. The importance of the discovery of new crystal structures goes well beyond materials science and chemistry – for instance, in geosciences it is well illustrated by the recent discovery of MgSiO3 post-perovskite [11-13], which has explained many anomalies of the Earth’s D” layer – see Fig.1.  [2]. .

 

USPEX_illustration1

Fig. 1. Structure of MgSiO3 post-perovskite (a) and an example of an evolutionary simulation using USPEX [6] predicting this structure without any experimental information (b). USPEX and other approaches have been reviewed in a recent book (c) edited by A.R. Oganov.

While there is an explosive methodological development, with many unique and powerful tools being constantly developed, there are significant barriers for effective dissemination of these developments to the users. These methodologies are very different from traditional simulation methods, and require some psychological barriers to be overcome – ideally, in the situation of a workshop. Interdisciplinarity of this whole field makes it not only exciting, but often hard to grasp – again, a workshop is ideal for such cross-disciplinary learning. We have planned a 5-day workshop with these issues in mind. The workshop will introduce the participants to the major concepts of this field, and will focus deeply on USPEX and the related tools. The participants will have an opportunity to perform their own simulations, analyze the results and discuss them with their peers.

This workshop aims at training a new generation of theoretical chemists (dealing with bulk solids, clusters and surface sciences), computational mineral physicists and materials scientists in this area of research, and at making experimentalists aware of and able to use the latest theoretical developments for their needs. Such interdisciplinarity will be useful for the participants, who will have an opportunity to learn from other related fields of research. The participants will have detailed tutorials on structure prediction for crystals, surfaces and nanoparticles and the USPEX code and how to analyze the rich data provided by this method using specifically developed advanced tools [14].

These tutorials will allow the students to tackle a range of problems from nano science , polymers and urface science, geosciences, crystallography, and materials sciences. There will be a plenty of time for discussions (20 minutes at the end of each talk, and informal discussions throughout the meeting). The workshop will include local excursions, wine tasting, bored de la Loire visit, … and a banquet.

The Workshop will consist of invited talks on USPEX and related tools to analyze the data. A contributed poster session and short scientific presentations will be organized, with ample space devoted to discussion.

Hands-on Tutorials on evolutionary crystal structure prediction using the USPEX code and on electronic structure computations will be organized during this workshop. Researchers with a proven experience in standard DFT and/or ab initio computations may participate in this tutorial.

 

 

ES’PA 2015

For beginners in periodic DFT – experimental chemists, theoretical chemists in molecular sciences, physicists, crystallographers, geoscientists , … – we will hold a special three-day hands-on tutorial in Poitiers University. This will be limited to 30 participants.

The hands-on tutorials are based both on the Vienna Ab initio Simulation Package code ([VASP) [15], and on the opensource and freeware QUANTUM ESPRESSO (QE) [16] . These periodic DFT codes are used within the USPEX [19] code to predict stable nanoparticles, polymers, surfaces and bulk structures given only the chemical composition. USPEX uses these codes for structure relaxations and energy evaluations.

The tutorials can be grouped into four main areas, which are (i) ground-state properties within periodic DFT, (ii) VASP / Quantum Espresso codes features (iii) structural optimisation (iv) “From bulk to surface” and nanoparticles (molecules) modelling. They will be complemented by introductory lectures related to the hands-on exercises (typically one to two keynote speakers per day and 6h hands-on laboratories plus open labs).

References:
[1] Modern Methods of Crystal Structure Prediction. Wiley-VCH. Ed. Oganov A.R. (2010).

[2] Maddox J. (1988). Crystals from First Principles. Nature 335, 201.

[3] Schön J.C., Jansen M. (2001). Determination, prediction, and understanding of structures, using the energy landscapes of chemical systems – Part I. Z. Krist. 216, 307-325.

[4] Martoňák R., Laio A., Parrinello M. (2003). Predicting crystal structures: The Parrinello-Rahman method revisited. Phys. Rev. Lett. 90, art. 075503.

[5] Goedecker S. (2004). Minima hopping: An efficient search method for the global minimum of the potential energy surface of complex molecular systems. J. Chem. Phys. 120, 9911-9917.

[6] Oganov A.R., Glass C.W. (2006). Crystal structure prediction using ab initio evolutionary techniques: principles and applications. J. Chem. Phys. 124, 244704.

[7] Lyakhov A.O., Oganov A.R., Valle M. (2010). How to predict very large and complex crystal structures. Comp. Phys. Comm. 181, 1623-1632.

[8] Oganov A.R., Chen J., Gatti C., Ma Y.-Z., Ma Y.-M., Glass C.W., Liu Z., Yu T., Kurakevych O.O., Solozhenko V.L. (2009). Ionic high-pressure form of elemental boron. Nature 457, 863-867.

[9] Ma Y., Eremets M.I., Oganov A.R., Xie Y., Trojan I., Medvedev S., Lyakhov A.O., Valle M., Prakapenka V. (2009). Transparent dense sodium. Nature 458, 182-185.

[10] Li Q., Ma Y., Oganov A.R., Wang H.B., Wang H., Xu Y., Cui T., Mao H.-K., Zou G. (2009). Superhard monoclinic polymorph of carbon. Phys. Rev. Lett. 102, 175506.

[11] Murakami M., Hirose K., Kawamura K., Sata N., Ohishi Y. (2004). Post-perovskite phase transition in MgSiO3. Science 304, 855-858.
[12] Oganov A.R., Ono S. (2004). Theoretical and experimental evidence for a post-perovskite phase of MgSiO3 in Earth’s D” layer. Nature 430, 445-448.

[13] Tsuchiya T., Tsuchiya J., Umemoto K., Wentzcovitch R.M. (2004). Phase transition in MgSiO3 perovskite in the earth’s lower mantle. Earth Planet. Sci. Lett. 224, 241-248.

[14] Valle M. (2005). STM3: a chemistry visualization platform. Z. Krist. 220, 585-588.

[15] VASP [http://cms.mpi.univie.ac.at/vasp/ ;

[16] Quantum Espresso [www.quantum-espresso.org ;

[17] ABINIT [http://www.abinit.org/ (2009) Computer Phys. Comm. 180, pp. 2582-2615

[18] SIESTA [http://www.icmab.es/siesta/index.php

[19] USPEX: [http://han.ess.sunysb.edu/~USPEX/

[20] recent publication with VASP: Trends in the Adsorption of 3d Transition Metal Atoms onto Graphene and Nanotube Surfaces: A DFT Study and Molecular Orbital Analysis. Valencia, H , Gil, A, Frapper, G (2010) J. Phys. Chem. C, pp. 14141-14153.

[21] recent publication with Quantum Espresso: [www.quantum-espresso.org ; P. Giannozzi et al. J. Phys. Condens. Matter 21, 395502 (2009).

 

Sponsors

A hearty thank you to the contributors who have already confirmed their sponsorships for DN-NSM 2015 international workshop in Poitiers.

 

DN-NSM 2015 (april 2015): Université de Poitiers, SUNY – Stony Brook University, Région Poitou-Charentes, Grand Poitiers, Réseau Français de Chimie Théorique, Groupe Chimie Théorique – E4 IC2MP.

Please take a moment to visit our sponsors’ websites and learn more about them. The generous support of our conference sponsors provides tremendous benefits for all attendees.

 

News