LOBSTER School on Chemical Bonding Analysis

Motivation and overview

The need to understand why a particular material is stable or not is of paramount importance for computational materials science. Today, atomic-scale materials modelling is clearly dominated by high-performance density-functional theory (DFT) using plane waves and pseudopotentials, but understanding the often incredibly complex results frequently benefits from a thorough chemical-bonding analysis using local orbitals. This 3-day school will teach ~25 participants how to carry out chemical-bonding analysis in general. In particular, the computer program LOBSTER will be introduced, which has been designed to suit the needs of high-performance materials simulations by being able to process output from VASP, ABINIT and Quantum ESPRESSO. The school will be the fifth in a series of previous successful ones in Germany, China, Japan, and an online school during the COVID-19 pandemic. It is targeted at researchers from various fields of computational science such as chemistry, physics, and materials science.

Methods for chemical-bonding analysis

As the search for new materials based on increasingly CPU-affordable electronic structure calculations gathers pace, and the amount of data generated by high-throughput calculations continues to accumulate, it becomes important to develop effective quantitative techniques to make sense of this wealth of information. While electronic structure calculations, predominantly based on DFT, have proven increasingly reliable and useful in understanding and predicting the properties of solids, the intricate contribution of local bonding networks in these materials escapes the most commonly used DFT analysis tools. A standard tool to probe the local character of the material’s band structure is the projected density of states (PDOS). Unfortunately, the PDOS only provides information about where electrons reside in the material, and not about how much local interactions contribute to the cohesive energy of the material. The crystal orbital Hamilton population (COHP) analysis, developed by Dronskowski and Blöchl in 1993, allows one to quantify the energy contribution of individual atomic bonds to the total energy of the system (the bond strength). This tool has established itself as a widely used method for understanding existing and new materials, because it provides a detailed quantitative way to establish links between the (macroscopic) properties of a material and its microscopic structure.

Lecturers

• Prof. Richard Dronskowski, RWTH Aachen University (Germany)
• Prof. Volker Deringer, University of Oxford (UK)
• Dr. Janine George, Federal Institute for Materials Research and Testing, Berlin (Germany) and FS University Jena (Germany)
• Dr. David Schnieders, RWTH Aachen University (Germany)
• Peter Müller, RWTH Aachen University (Germany)

Venue

The LOBSTER School 2024 will take place in the main campus of Aalto University, in the Helsinki metropolitan area. The School’s venue is Aalto Design Factory‘s Studio, Puumiehenkuja 5A, Espoo, 02150 Finland.

Aalto University is very well connected within the Helsinki metro area. The Otaniemi campus can be reached via metro (“Aalto University” stop) and the light rail (“Maari”, “Aalto-yliopisto” and “Otaranta” stops, from west to east). Please visit the website of HSL, the company operating the public transport system in the Helsinki metro area. This includes buses, the metro, trains, downtown trams, the light rail, and some municipal ferry services (e.g., to the Suomenlinna fortress island). Public transport in the Helsinki metro area is safe, clean and reliable. The easiest way to use the public transport system is to download the HSL app on your phone.

The Aalto University campus can be reached from Helsinki airport, e.g., by combining the train with the metro (changing at Helsinki’s Central Railway Station). Non-collective public transport options like taxis are also available, including popular apps like Uber; these are significantly pricier than collective transportations but might be more convenient depending on the situation (e.g., if you are in a hurry to reach the airport).

Schedule

This is the preliminary schedule. More detailed information will be provided later.

Participants

Online resources

• LOBSTER website (for code download, etc.): http://cohp.de/
• Github repository: https://github.com/davSchnieders/LOBSTERSchool
• wxDragon fro visualization: Linux version; Windows version
• Step-by-step procedure:
  1. Download and unpack the LOBSTER code
  2. Add the LOBSTER binary to your PATH: export PATH=/lobster_code_root_directory:$PATH
  3. Clone the github repo: git clone https://github.com/davSchnieders/LOBSTERSchool.git
  4. Download and unpack wxDragon
  5. Make the wxDragon binary executable (from within the wxDragon directory): chmod +x wxDragon
  6. Add the wxDragon binary to your PATH: export PATH=/wxDragon_code_root_directory:$PATH
• To install LobsterPy, you can just do: pip install lobsterpy (under Ubuntu, you may also need to upgrade your requests package, e.g.: pip install requests==2.25.0)

Registration

The registration is now closed.

Local organizers

• Dr. Miguel Caro, Aalto University (Finland)
• Dr. Rina Ibragimova, Aalto University (Finland)
• Dora Javor, Aalto University (Finland)

Sponsors

In addition to organization support by OCAMM, the LOBSTER School 2024 is financially supported by the Psi-K network, the Aalto University Deparment of Chemistry and Materials Science, and the Finnish CECAM node.