@PhDThesis{ itlic:2013-005, author = {Emil Kieri}, title = {Numerical Quantum Dynamics}, school = {Department of Information Technology, Uppsala University}, department = {Division of Scientific Computing}, year = {2013}, number = {2013-005}, type = {Licentiate thesis}, month = oct, day = {15}, note = {Included papers available at \url{http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-179058}, \url{http://www.it.uu.se/research/publications/reports/2013-019/}, \url{http://www.it.uu.se/research/publications/reports/2013-007/}.} , abstract = {We consider computational methods for simulating the dynamics of molecular systems governed by the time-dependent Schr{\"o}dinger equation. Solving the Schr{\"o}dinger equation numerically poses a challenge due to its often highly oscillatory solutions, and to the exponential growth of work and memory with the number of particles in the system. Two different classes of problems are studied: the dynamics of the nuclei in a molecule and the dynamics of an electron in orbit around a nucleus. For the first class of problems we present new computational methods which exploit the relation between quantum and classical dynamics in order to make the computations more efficient. For the second class of problems, the lack of regularity in the solution poses a computational challenge. Using knowledge of the non-smooth features of the solution we construct a new method with two orders higher accuracy than what is achieved by direct application of a difference stencil.} }