CAMD Summer School 2026

Announcement: https://www.fysik.dtu.dk/english/research-sections/camd/events/summer-school-2026

Summer school exercises

The Summer School includes a number of Projects, where you will need to run calculations on the DTU central computing facilities. This requires some setup, which is described below.

The computer system

The DTU computer system (known as the ‘G-databar’ for obscure reasons) consists of a login node (named login.gbar.dtu.dk or gbarlogin) and a number of compute nodes. Some of the compute nodes are reserved for batch jobs, some allow interactive jobs. You need to run on the interactive compute nodes, running on the login node will overload it.

Instructions

There are two main ways to log in to the DTU system, SSH and ThinLinc.

SSH is probably the most convenient. Programs on the remote system will be able to open windows on your computer just like local programs.

ThinLinc opens one big window with a Unix desktop running on the DTU computer. Putting this window in full-screen mode makes your computer act as a graphical terminal. Programs on the remote computer open their windows within this desktop window.

Which one you choose is a matter of taste. We find ssh slightly more convenient once it is set up, but thinlinc may be a bit easier to set up initially.

Setting up ssh for the first time

The instructions depend on the operating system you use

• Setting up SSH for the first time (Windows)
• Setting up SSH for the first time (Linux / macOS)

Setting up thinlinc for the first time

IMPORTANT: You should either set up SSH or ThinLinc, no need to do both!

• Setting up ThinLinc the first time (All laptops)

Using the DTU computers

• Using the DTU computers interactively
• Submitting jobs on the DTU computers

iPad users (strongly discouraged)

Working from an Ipad is very inconvenient, but possible.

• Using an iPad

Introductory slides

The slides from the introduction to the exercises (Sunday) can be found here: Intro_ASE_Databar.pdf

Projects

Choose a project according to your interests. The projects contain brief descriptions of what aspects of GPAW you learn from them.

• Introduction to Python and ASE and some useful libraries
  • Importing the necessary modules
  • Variables and data types
    • A list is an ordered collection of arbitrary objects
    • A dict is a mapping from keys to values
    • A tuple is an ordered collection like a list but is immutable
  • NumPy
  • Plotting with matplotlib
  • ASE (atomic simulation environment)
    • Everything starts with a structure!
    • Setting op a molecule using the Atoms object
    • Setting up a periodic structure
  • Nitrogen on copper
    • Exercise of the relaxation of a molecule on a surface
  • Band structure
• Catalysis
  • Part 1: N₂ adsorption on a flat Ru surface
    • Catalysis: Dissociative adsorption of N₂ on a metal surface
  • Part 2: Splitting N₂: initial and final geometry
  • Part 3: Learning about Nudged Elastic Band
    • Introduction to Nudged Elastic Band (NEB) calculations
    • Parallelisation
    • Input parameters
  • Part 4: Run a parallel NEB calculation
  • Extra exercise: Vibrational energy
    • Extra exercise - Vibrational energy
  • Extra material: Convergence test
    • Convergence checks
• Magnetism in 2D
  • Part 1: Critical temperature of CrI₃
    • DFT calculation - finding the atomic structure of CrI₃
    • A bit of theory
    • DFT calculation of \(J\)
    • More theory
    • Magnetic anisotropy from DFT
  • Part 2: Noncollinear magnetism in VI₂
    • Optimizing the atomic structure
    • Magnetic anisotropy
    • DFT calculations in a repeated cell
    • Calculating J
    • Noncollinear configuration using a super cell
    • Noncollinear configuration using spin spirals
    • Anisotropy and exchange coupling from noncollinear DFT
    • Critical temperature?
  • Part 3: Find new ferromagnetic monolayers with high critical temperatures
• Machine Learning
  • Part 1: Inspection of database
  • Part 2: Machine Learning
  • Part 3: Test and Evaluate the Model
• Excited States
  • Part 1: Setup of the structure and bandstructure calculations
    • Introduction to band gaps and band structures
  • Part 2: Quasiparticle bandgap
    • Quasiparticle bandgap using GW approximation
  • Part 3: Absorption spectrum
    • Calculating absorption spectra
  • Part 4: Excitonic effects and Discussion
    • Inclusion of excitonic effects and Discussion
• Batteries
  • Part 1: Li intercalation energy in graphite
    • Li intercalation in graphite
    • Graphite
    • Li metal
    • Li intercalation in graphite
    • Bonus
  • Part 2: Equilibrium potential of a LiFePO4/C battery
    • Equilibrium potential
    • FePO₄
    • LiFePO₄
    • Li metal
    • Calculate equilibrium potential and uncertainty
    • Bonus
  • Part 3: Transport barriers and Voltage profile
    • Transport barrier of Li in graphite
    • Bonus: Barrier dependence on interlayer distance
    • FePO₄ with one Li
    • Bonus: LiFePO₄ with one vacancy
    • Bonus: BEEF for FePO₄ + Li and LiFePO₄ - Li
• Computational workflows
  • Part 0: The TaskBlaster tutorials and documentation
  • Part 1: Simple materials workflow
    • Set up structure optimization
  • Part 2: Add ground state and band structure tasks
  • Part 3: Parametrize workflow over multiple materials

Instructions for instructors

Instructions for the people testing and developing the projects can be found here:

• Logging in
• Creating an SSH key pair (while at DTU!)
  • Creating a key pair on Mac or Linux
  • Creating a key pair on Windows
• Setting up the Virtual Environment etc