European Commission logo
italiano italiano
CORDIS - Risultati della ricerca dell’UE
CORDIS

Computer simulations of thermally excited molecules and materials by first principles

Final Report Summary - TEMM1P (Computer simulations of thermally excited molecules and materials by first principles)

With the rapid development of computational sciences and of high-performance computing, first principles computer simulations have become a standard for the simulation of processes in physics, chemistry, biology and materials science. Moreover, the quality of first principles methods, most of all of density-functional theory, reached recently that of experiments, which allows the prediction of new forms of condensed matter, including novel molecules and nanomaterials with specially designed building units. However, these simulations refer to the electronic ground state, while in reality and experiment the materials are exposed to elevated temperatures, where also the electronic structure should be considered to be thermally excited.
We develop, implement and validate methods to simulate processes at thermally elevated temperatures. Our target applications are the formation of fullerenes and endohedral fullerenes in arc discharge plasma, thermolysis of ammonia boranes, chemical reactions of oil sands cracking at high temperature and pressure, ion diffusion in clay-mineral nanotubes, and mass spectrometer chemistry including the formation of new molecules with untypical bonding properties and the chemical reaction of methane with late transition metal and rare earth ions, a hopeful way to produce molecular hydrogen from natural gas. All applications have in common that they occur at high temperature and partially high pressure, and hence require similar computational methods. With this project we would like to initiate a Transfer of Knowledge scheme where we create synergies in developing these methods, implement them for their use in latest supercomputer facilities, and have well-trained personnel to be able to operate them in the individual workgroups. The Exchange Programme includes long-term stays of graduate students (ESR) as well as shorter-term stays of research staff (ER) and professors.
Computational chemistry has developed to be an indispensible tool to understand molecular structure, molecular properties and chemical reactions. Still, the role of computational chemistry is - at present - rather to be a complementary tool to illustrate experimental results. In the near future we expect this role to change; in several fields computational chemistry will change such that predictions will be first made on the grounds of computer simulations, before elaborate and expensive experiments will be made.
The main showstopper in making predictions in silico is that the fundamental quantity to control chemical reactions is the Free energy or the Gibbs energy, and hence temperature effects play a significant, at high temperatures often a dominant, role. Computational methodologies are still much less developed in describing temperature-dependent effects, and this consortium will work on providing those methods and by applying them to state-of-the-art chemical problems in diverse fields, hence disseminating them to a wide audience of chemists, materials scientists and physicists.
The Objectives are headed by the principal goal, the development of computational methods to simulate temperature-induced and high-temperature processes. The second objective is devoted to the scientific development of the participating groups to strengthen their expertise and profile by the Transfer of Knowledge. The methods will be applied in three state-of-the-art fields of chemistry: gas phase chemistry, high-temperature formation of molecules, and the simulation of reactions in supercritical fluids. Two of these applications are motivated by environmental chemistry (production of hydrogen from natural gas and oil sands exploitation with significantly less impact to the environment), and two to the formation of new molecules (the formation of metallofullerenes and the formation of molecules with new bonding types). The final Objective is to disseminate our methods at the best possible level and to exploit the Transfer of Knowledge to boost the research capacities in the participating laboratories. The Objectives are directly associated to Work Packages.

Objectives
1. Development of methods and software which allow the simulation of chemical reactions, molecular formations and intramolecular processes at elevated temperatures. This project will create synergies which make these developments possible.
2. Transfer of Knowledge between the laboratories in order to master the application of new methods, different software and the use of high-performance computational facilities by exchange of scientists and by the organisation of two summer schools
3. The prediction and fundamental understanding of chemical reactions and new molecular structures in ion traps characterised by mass spectroscopy
4. Simulate the plasma formation of molecular structures, in particular of endohedral fullerenes
5. The simulation of chemical reactions in super-critical fluids for refining oil sands and thermolysis.
6. To disseminate the methods developed in Objective 1 and to improve the research capacities of the partner laboratories through the benefits of networking
The consortium has introduced new methods into popular codes of quantum chemistry. Most notably is the collaboration with major leading scientific software companies, such as SCM N.V.(ADF BAND, DFTB) and Gaussian Inc. This way, synergies between academic and private sector are generated, in particular concerning the dissemination of results, the long-term maintenance of code, and the transfer of codes to different computational architectures. The latter example gets evident as typical academic codes are Linux based without user-friendly interfaces, while our commercial partners provide graphical user interfaces and deliver the software for Windows and Macintosh computers.
Milestone achievements in the software developments are the availability of a practical QM/MM scheme, the implementation of funnel metadynamics, and the first successful tests of alternatives for matrix diagonalization for realistic systems.

The consortium is historically strong on tackling challenging application projects. This is reflected by few highlights that should be mentioned in this summary:
Oil sands upgrading is a major controversially discussed topic: While oil sands are candidates to shift peak oil to later times, their exploitation remains a major environmental issue due to the enormous water resources that are needed for this process, and for the associated release of contaminated water into the environment. We propose alternatives that would reduce the need of water for oil sand exploitation to a minimum. The concept is to take advantage of the high temperatures and pressures in the reservoirs, and to catalytically convert the high boiling fractions into light hydrocarbons that can simply be harvested. In other words, the refinery will be done in the deposit. A crucial necessity is to understand if this conversion is possible at all, and how could it be optimized. We explore therefore the catalysis of molybdenum carbide. The first results on small hydrocarbon molecules are promising, and we have developed an approximate DFT tool to model more complex reactions.
Even though the cheap availability of methane (natural gas) was slowing down the technological developments towards a hydrogen economy, this topic remains a very important one for the future. A important challenge is the efficient transport of hydrogen. As low-cost carrier system with excellent volumetric and gravimetric hydrogen storage capacity ammoniaboranes have been identified. The challenge is the controlled release of hydrogen, what is typically achieved using thermolysis. As alternative, our results suggest to catalyyotically release hydrogen, what will result in a more controlled release reaction and in a more homogeneous composition of products (in this case: waste) that can be recycled for reuse.
A third project is of more academic nature. Boron becomes recognized as very interesting elements as it, similar to carbon, can be incorporated in 3D and in planar forms into molecules and materials.
Boron clusters are used as ionic liquids. However, their planar counterparts may be first prototypes of quantum rotors that require fundamental studies. This consortium has identified how planar boron clusters can be produced from standard chemicals (i.e. B12I122- dianions that are a standard component of ionic liquids). Moreover, the consortium is currently investigating the intriguing bonding situation in these species.
The consortium has been very active in education of graduate students. As highlight, it has organized a summer school that took place in June 2014 at Jacobs University Bremen.
The consortium is continuing to develop and implement methods for the description of thermally excited quantum systems, and sustainable development has been ensured by teaming up with scientific companies and by obtaining primary funding from different sources. It takes its responsibility to train early stage researchers on these methods, by individual training and by summer schools. The partners act successfully as academic network, e.g. in the supervision of PhD theses. In this vein, many co-mentoring agreements have been achieved and have led to very successful PhD theses at the partner universities.