Hi all, I am forwarding a seminar announcement from Computational Science and Engineering regarding a talk tomorrow by Emily Carter. It looks like she will be speaking about orbital-free DFT. --- Quantum Simulations of Materials at the Mesoscale: Physics, Algorithms, and Applications Emily A. Carter – Gerhard R. Andlinger Professor in Energy & the Environment, Princeton University Abstract: Many materials phenomena are controlled by features at the mesoscale, i.e., a length scale above atoms but below the micron scale. In addition to the fashionable example of nanostructures, other practical examples abound. For instance, the mechanical properties of metals are largely controlled by the nucleation and motion of dislocations and their interaction with other defects (e.g., grain boundaries, solutes, precipitates) in crystals. Experiments (e.g., electron microscopy) provide post-mortem examination of these features. By contrast, computer simulations can interrogate these defects in situ. Of course, reliability of the simulations is always an issue. Our research aims to develop predictive simulation tools that do not rely on any experimental input, such that they produce a truly independent source of data for comparison with experiment. This assumption/empirical-input-free approach requires going back to basic physical laws, namely those of quantum mechanics to describe electron distributions in materials. Normally such techniques are prohibitively expensive for simulating more than a few hundred atoms on supercomputers. But because of algorithmic improvements to a quantum mechanics method (orbital-free density functional theory) that makes it scale fully linearly with system size, we are now able to simulate fully quantum mechanically and accurately large scale defects that play key roles in plastic deformation and ductile fracture of main group metals and metal alloys, with accuracy rivaling the most accurate solid state quantum mechanics methods available. Recent advances in the physical approximations used to evaluate the electron kinetic energy (via new nonlocal kinetic energy density functionals) and the electron-ion interaction have extended the range of reliability of this technique beyond main group metals to semiconductor materials, and very recently, to transition metals. Current applications are focused on predicting the behavior of dislocations in aluminum and magnesium and their alloys; ultimately we hope to guide optimization of the composition and microstructure of lightweight metal alloys (by finding a sweet spot in the ductility-strength tradeoff) that can be used to improve the fuel efficiency of vehicles. WEDNESDAY, November 30, 2011 4:00-5:00 pm Room 1-390 Thanks,  · Jiahao Chen · MIT Chemistry · _______________________________________________ Aspuru-meetings-list mailing list Aspuru-meetings-list(a)lists.fas.harvard.edu https://lists.fas.harvard.edu/mailman/listinfo/aspuru-meetings-list