1. Could you explain the significance of your article to the non-specialist?

Covalent interactions play a key role in chemistry while non-covalent interactions play a decisive role in biodisciplines. The structure of liquids, solvation phenomena, molecular crystals, the structures of biomacromolecules and molecular recognition are several phenomena fully determined by non-covalent interactions. Covalent and non-covalent interactions differ considerably (the latter are by 1 or 2 orders of magnitude weaker) and have completely different origin. While theoretical description of covalent interactions is nowadays routine, description of non-covalent interactions belongs to the most difficult tasks of today's computational science.

2. What has motivated you to conduct this work?

To understand the function of DNA it is necessary to understand its structure. The bonding in planar H-bonded DNA base pairs was well understood but the role of stacking interactions, their origin and magnitude was not clear. Only the most accurate calculations on both interaction motifs performed recently revealed their relative importance and it is now clear that it is stacking which dominantly contribute to stability of DNA.

3. Where do you see this work developing in the future?

It is necessary to pass from static description to dynamical one, i.e. to perform the molecular dynamic simulations. The empirical force field used in these calculations nowadays should be, however, replaced by quantum chemical description and "on-the-fly" ab initio molecular dynamics will represent the method of the future. The main goal is to develop very fast and accurate quantum chemical method suitable for investigation of extended biomolecular clusters. It is necessary to mention that first promising methods already exist.

4. Are there any particular challenges facing future research in this area?

Basically we are at very beginning and the whole area of biomolecular interactions and their applications in various biological processes is waiting for detailed study.