Several groups and departments in Finland active in high-end computational science are affiliated with the Node. Their activities are described briefly below.
COMP is an Academy of Finland Centre of Excellence in Computational Nanoscience at Aalto University. The basic strategy of COMP is to develop and apply cutting-edge theoretical and computational methods and the best available computing resources in attacking challenging problems in condensed-matter and materials physics. This includes modelling and simulation of wide classes of materials and related phenomena, ranging from novel semiconductors to biological and soft matter. The research interests range from electronic and structural properties of materials to their processing as well as to device and systems behavior.
The COMP Centre of Excellence strives at a multiscale approach to condensed-matter and materials research, ranging from the quantum world of ångströms and femtoseconds to macroscopic length and time scales. The research covers such areas as electronic structure and related properties, mesoscopic dynamics and transport, and the complex behavior of nonequilibrium and disordered systems. Of particular interest are the nanoworld phenomena, the understanding of which depends on predictive modelling and simulation.
In addition, the work carried out at COMP involves research into theoretical methods as well as simulation and computing techniques, such as algorithms, parallel and grid computing, and scientific visualisation.
NMR (Oulu University)
The Nuclear Magnetic Resonance (NMR) Research Group, Department of Physics, University of Oulu is active in the theory and computation of magnetic resonance. We take interest in the rich phenomenology involved in the interaction of the electron cloud of atoms, molecules and solids with static magnetic fields (external fields of fields due to nuclear and electronic spins) and dynamic electromagnetic fields, such as due to laser irradiation. We develop and apply both quantum-chemical and periodic electronic structure methods, as well as apply a rich panoply of molecular simulation methods, in this context. We have made contributions in the (a) relativistic and (b) dynamic and solvation effects on magnetic resonance observables, as well as (c) theory of paramagnetic NMR, and (d) the novel field of nuclear magneto-optic spectroscopy. Particularly in the last topic we have predicted the existence of a nuclear magneto-optic chemical shift, which may pave the way to a whole family of novel, sensitive spectroscopic methods as well as high-resolution means of magnetic imaging. At the Department of Physics of the University of Oulu, computational physics is also applied in the fields of electron spectroscopy, cellular biophysics, and condensed-matter theory.
Computational materials science and nanoscience (University of Helsinki)
The joint computational research groups of Prof. Kai Nordlund (Department of Physics) and Adj. Prof. Flyura Djurabekova (HIP) uses sequential and concurrent multiscale to examine far-from-equilibrium materials processes in all classes of materials. Current emphasis areas are ion beam processing of carbon nanotubes, nanoclusters and nanowires; structural and optical properties of nanoclusters embedded in solids; plasma-wall interactions and radiation damage in fusion reactor materials and sparking in future particle accelerator materials.
One of the major areas of method development is making an atom-level theoretical model of surface behavior under high electric fields. Our model aims to explain the physical limitation of a metal surface due to electrical breakdowns at the fields well below the critical values known to cause field-emitted removal of atoms. We model all three main stages of plasma development ignited in ultra-high vacuum, i.e. plasma onset, plasma evolution and surface damage due to the plasma discharge. The main emphasis of the presentation will be the triggering process of plasma ignition event due to the effect of a high electric field. We develop new methods to combine the atom and electron dynamics within a classical molecular dynamics approach to be able to follow the complex processes taking place in the top layers of conducting surfaces.
The work in the group has resulted in more than 400 refereed publications and 20 PhD theses since 1999.
Computational aerosol physics (University of Helsinki)
The computational aerosol physics (CAP) group at the University of Helsinki uses a palette of different modeling approaches to calculate formation rates and properties of atmospheric clusters and nanoparticles. The end users of our research are air quality and climate modelers.
To capture the properties of the smallest clusters, we need to perform electronic structure calculations, including both density functional theory and correlated wavefunction-based methods. Statistical mechanics is then used to convert quantum chemical formation free energies to cluster evaporation and fragmentation rates, and kinetic theory to model the cluster-cluster and cluster-molecule collisions. The collision and evaporation rates a fed into our Atmospheric Cluster Dynamics Code, which solves the time evolution of the cluster size distribution, and also gives the net formation rates for the largest studied clusters. In addition, first-principles molecular dynamic simulations are employed to investigate dynamic features of the cluster formation process, and e.g. obtain more reliable effective cluster collision rates. Unfortunately, these methods are computationally far too demanding to describe the entire new-particle formation process. Therefore, quantum chemical results need to be combined with classical thermodynamic models, the results of which in turn must be parameterized for efficient use in larger-scale models.
Computational physics (Tampere University of Technology)
Computational Physics is one of the three scientific corner stones of the Department of Physics at Tampere University of Technology. Overall the Computational Physics unit deals with various themes related to the development and characterization of complex materials. The main research areas focus on biologically and medically relevant molecular systems, design of novel material concepts, quantum dynamics, electronic structure theory, and spectroscopies of complex materials. In addition to unlocking tedious research questions in these fields, the unit also strongly contributes to the development of new simulation techniques over a multitude of scales: quantum-mechanical ones, atomistic and molecular scales, and the bridging of these scales to the continuum limit. The unit is a member of two Centers of Excellence chosen by the Academy of Finland, it is highly active in its research field (with about 250 publications during the last five years), and it is strongly committed to bridging its simulation work to experiments through intensive collaborations.