Second-Order Electronic and Anharmonic Vibrational Perturbation Calculations on Ice Ih

Matthew Hermes, University of Illinois at Urbana-Champaign

Usage Details

The use of embedded fragmentation techniques, which are trivially and extremely parallelizable, to perform sophisticated ab initio electronic structure calculations on systems which were considered intractably large just a few years ago is currently a hot topic of research. However, anharmonic vibrational structure calculations lag behind their electronic counterparts because phonons are fundamentally delocalized, and hence it is difficult to apply fragmentation techniques to solving the vibrational structure problem. Our lab has developed novel anharmonic vibrational structure methods, which render such calculations possible. I will use Blue Waters to perform completely ab initio anharmonic vibrational structure calculations on ice as a paradigm for simulations in which all electronic and vibrational properties are computed by members of systematic hierarchies of methods which converge to the exact limit. Blue Waters’ large parallel capacity will allow me to take full advantage of the parallelizability of the necessary electronic structure calculations using embedded fragmentation methods, permitting much more sophisticated calculations closer to convergence.