Theoretical support: overview
In order to enable a deeper understanding of material properties, characterization methods and fabrication processes, theoretical support is an integral part complementing experimental methods conducted at the CzechNanoLab infrastructure. The theoretical analysis is based on state-of-the-art software tools, which are in part actively developed in house. Complex models that require high-performance computing use the computational resources provided by the Metacentrum and IT4Innovation facilities.
Our aim is to provide a more in-depth insight into experimental measurements acquired in CzechNanoLab facilities. Therefore, we offer theoretical support including atomic-scale modelling. Based on different toolkits, we perform classical and quantum calculations depending on the complexity of the problem. Core competence is the optimization of the atomic and electronic structure of systems under study, which can be tailored to address specific properties or processes as required by the experiments.
We provide theoretical support based on electronic structure calculations using total energy DFT calculations employing different codes:
- home-built large scale local orbital DFT Fireball code including thousands of atoms
- other available DFT codes: VASP, FHI AIMS, Abinit, Wien2K, KKR-GF
Optionally, we also employ calculations beyond single-determinant DFT methods such as GW, DMRG or DMFT.
- DFT calculations of interaction and activation energies of molecules on surfaces
- QM/MM simulations of on-surface chemical reactions
- dynamics of chemical reactions (rate equations, kMC)
- Linear response Kubo
- Non-equilibrium Green’s function within Fireball and TranSiesta codes
Symmetry analysis of crystals
Magnetic dynamics simulations
- Xtalsim - Atomistic structural model for semiconductor materials
This software allows us to study semiconductor materials and heterostructures at atomistic length scales based on empirical interaction potentials. This computationally efficient model is also capable of simulating epitaxial growth processes to study the evolution of interface morphologies.