science 27.10.2017 16:36

Slovenian scientists achieve breakthrough in computer simulations of molecular dynamics

Ljubljana, 27 October - Scientists at the National Institute of Chemistry have developed new methods for computer simulations of the movement of molecules in soft matters such as liquid crystals, polymers and colloids, in what is seen as a breakthrough that could play a major role in the development of nanotechnology.

Ljubljana
Researcher at Slovenia's Institute of Chemistry Matej Praprotnik.
Photo: Anže Malovrh/STA

Ljubljana
Researcher at Slovenia's Institute of Chemistry Matej Praprotnik.
Photo: Anže Malovrh/STA

Ljubljana
Researcher at Slovenia's Institute of Chemistry Matej Praprotnik.
Photo: Anže Malovrh/STA

Ljubljana
Researcher at Slovenia's Institute of Chemistry Matej Praprotnik.
Photo: Anže Malovrh/STA

Ljubljana
Researcher at Slovenia's Institute of Chemistry Matej Praprotnik.
Photo: Anže Malovrh/STA

According to Matej Praprotnik, the head of the molecular modelling department at the reseach centre, simulations are a bridge between theory and experiments in that they can explain the macroscopic characteristics of a system based on their characteristics at the microscopic level.

Contrary to the standard techniques, the new simulation methods push the limits of the molecular system and allow for the exchange of energy and matter with the environment in and outside of thermodynamic balance.

In experimental situations, open systems, which exchange mass, momentum and energy with the environment, are the most common.

Until now, simulations of molecular dynamics in open systems have been rare because of the complexity of the procedure.

To truly capture the simulated systems, they would have to be infinite, meaning infinite memory and infinitely powerful processors.

To overcome this limitation, scientists use tricks such as periodic fringe conditions with a constant number of molecules.

To put it simply, scientists simulate a box with a finite number of particles and then copy it in all directions, which gives the scientists a periodic picture of the entire system while the simulation box retains a finite number of molecules.

The new methods developed by Slovenian scientists allow molecules to leave or enter the simulation system, and make simulations suitable for new technologies in nanotechnology, nanomedicine or nanofluidics.

Praprotnik cited as an example simulations of water flow through nanotubes for obtaining drinking water by desalination, which will become increasingly important in the future.

According to him, simulations allow the scientists to direct their research and thus save time and money. In addition, "you can do many things that would be very hard to achieve in the real world such as studying the movement of molecules at very low temperatures or at high pressure".

The interview is available at https://youtu.be/SYfm3YZ6ECM