Computational modelling is a part of the natural sciences that has experienced probably the most rapid growth in the last decade. With the advent of large scale computational resources, a new way of studying the properties of matter, of predicting the behaviour of new substances and of validating statistical hypotheses has become available. This third pillar of the natural sciences is by its very nature a truly interdisciplinary undertaking; modelling aspects from seemingly unrelated science subjects can be easily accommodated on very similar computational architectures. This leads to a useful economy of scale. As a world-class initiative, the Science City Research Alliance realizes this and hence invested in a common essential and dedicated IT infrastructure to support the science in each of the themes.