Abstract

Path-integral based methods combine quantum statistics with classical dynamics to offer a computationally feasible way of introducing nuclear quantum effects into molecular dynamics simulations. A variety of path-integral methods are available, but many are known to perform poorly when estimating certain quantities. A key problem is the introduction of an artificial frequency shift when calculating infrared spectra. Quasicentroid molecular dynamics (QCMD) is a new path-integral method that circumvents this issue giving both accurate lineshapes and frequencies. This talk will introduce the family of path-integral methods and go into detail of the specifics of QCMD . We will then present results on the extension of QCMD to polyatomic species, using ammonia as a testing ground, and discuss the advantages and disadvantages of the method.