A Quickstep forward: development of the CP2K/Quickstep code and application to ice transport processes

Density Functional Theory is an atomic scale tool which can be used to learn about the structure and behaviour of substances, especially when atoms or molecules react with one another. For instance, it has been used to tell us about how the structure of water changes when it becomes acid or alkali. It is true to say that it has revolutionised our understanding in many aspects of science, and one of the originators (Walter Kohn) was awarded the Nobel Prize (in 1998) for developing the underlying theory which is at the heart of DFT computer simulation software. Since the first implementation of DFT, several flavours of DFT have been developed that have generally increase accuracy of this method, allowing scientists to calculate energies for chemical reactions with amazing accuracy. The usefulness of this method is increased when computer processors can be utilised in parallel to divide up the calculation into small sub-calculations. Currently Intel are marketing their Duo core processors for desktop and notebook computers where the computer is able to split the computational burden over two processors. The same principle is used on national supercomputers, where over 1000 processors can be used to make very demanding calculations (that would take 1000 years on one processor) into a far more manageable task, taking one year on 1000 processors, assuming the program was perfectly efficient. In reality, it is very difficult to obtain such efficient parallelism / special tricks need to be used to use the computer processor performance. This application seeks funding to develop a popular new piece of software that it can run far more efficiently on the new national supercomputer.Once the develpoment has taken place, we will look in detail at the structure and nanoscopic defects in ice. Understanding the structure and behaviour of microscopic imperfections in the ice structure will lead us to better understand how it conducts but more generally, how these defects influence the stability of ice. The latter is becoming ever more topical and important as we seek to understand how ice melts in order to better estimate the influence of temperature on glacial ice sheet.