Molecular modelling - Opportunities for soil research

Computational chemistry (CC) is a young science which develops rapidly. This is intimately connected with the increase in computer power and the recent rapid improvement of PCs and work stations. Although at present seldom used, numerous applications in soil science, especially in pollution research, can be envisaged. New techniques as e.g. the ONIOM method make it possible to investigate interactions within quite large systems of up to 100 atoms with high accuracy. Another interesting field for CC are studies of the hypothetical structure of humic substance models. These can be used for investigations of interactions with various pollutants (e.g. "bound residues"). In this paper we examplify quite different applications of CC in soil research: (i) the interaction of organic acids with aluminium, (ii) the hypothetical structure of humic substances and their interactions with pesticides and (iii) the use of the ONIOM technique to study adsorption sites on clay minerals.