Seminar: Henrik Larsson

The Simons Center for Computational Physical Chemistry at NYU regularly hosts visiting scholars to discuss their work.  Join us on December 9th for a presentation by Henrik Larsson of the University of California, Merced:

Tensor network methods for computing vibrational and electronic states

Abstract

Tensor network states (TNS) have independently advanced the fields of condensed matter physics, electronic structure theory, and vibrational quantum dynamics. Despite their similarities, TNS algorithms applied to electronic and vibrational systems differ substantially, and an in-depth comparison of their strengths and limitations is lacking. In this talk, I will explore the application of the density matrix renormalization group (DMRG) -traditionally used for condensed matter and electronic structure simulations- to vibrational quantum dynamics. I will compare the performance of DMRG with the multi-layer multi-configuration time-dependent Hartree (ML-MCTDH) method, an established algorithm for vibrational systems. I will use these methods to simulate the vibrational spectra of the Zundel ion (H₅O₂⁺) and the 33-dimensional Eigen ion, two highly challenging systems characterized by large-amplitude motion and Fermi resonances. 

Finally, I will demonstrate how a technique widely used for MCTDH can improve electronic structure DMRG calculations. Using this technique, I will present the computation of a highly accurate potential energy curve (PEC) for the chromium dimer, a grand challenge in small molecule spectroscopy where theory and experiment have been at odds for decades. The computed PEC allows for a new analysis of existing experimental data and suggests a reassignment of the vibrational levels of the chromium dimer.

All Simons Center seminars are held in Waverly 540.  Refreshments will be served at 10:45, and the seminar begins promptly at 11:00 AM ET.      

Or join via Zoom:  https://nyu.zoom.us/j/99318701420?pwd=eGVvSzlKWFRlV0ZldnJJbjhYVUtEQT09