Software Development for Integrating Molpro with Newton-X for Adiabatic and Non-adiabatic Excited State Dynamics

  • Author / Creator
    Wang, Zhibo
  • An interface between the non-adiabatic dynamics software Newton-X and the quantum chemistry software package Molpro has been created for select methods: second order local coupled cluster (LCC2), second order local algebraic diagrammatic construction (LADC(2)), and complete active space self-consistent field (CASSCF). This interface incorporates Molpro electronic structure methods for the generation of absorption spectra, adiabatic dynamics, and non-adiabatic dynamics via surface hopping. Functionality of the interface was tested with (i) absorption spectra generation using LCC2 and LADC(2) sampling of a Wigner distribution of the ground state for thiophene and the B-Te-6-B tellurophene, (ii) absorption spectra for thiophene using CASSCF, and (iii) non-adiabatic dynamics for methaniminium and thiophene using CASSCF.
    For the LCC2/LADC(2) integration, CAM-B3LYP/cc-pVDZ optimized geometries and normal modes were used as the initial seed for the ensemble of Wigner distribution sampled geometries. These sampled geometries were then processed with LCC2/LADC(2) to generate UV-Vis absorbance spectra for the two aforementioned molecules: thiophene and B-Te-6-B. Spectra generated compare reasonably well with experimentally measured spectra, although there are blue-shifts possibly due to the use of modest-sized basis sets for computational efficiency. There are also discrepancies in peak intensities for B-Te-6-B but these could be accounted for by incorporating more excited states, at increased computational cost.
    Simulations using the integration of Molpro for CASSCF dynamics were successful in replicating literature results for a methaniminium trajectory and of a thiophene ring opening involving a non-adiabatic transition from the first excited state to the ground state. This CASSCF implementation also permits UV-Vis spectrum generation via sampling a ground state Wigner distribution and adiabatic dynamics, where trajectories are propagated on a single potential energy surface.

  • Subjects / Keywords
  • Graduation date
    Fall 2019
  • Type of Item
  • Degree
    Master of Science
  • DOI
  • License
    Permission is hereby granted to the University of Alberta Libraries to reproduce single copies of this thesis and to lend or sell such copies for private, scholarly or scientific research purposes only. Where the thesis is converted to, or otherwise made available in digital form, the University of Alberta will advise potential users of the thesis of these terms. The author reserves all other publication and other rights in association with the copyright in the thesis and, except as herein before provided, neither the thesis nor any substantial portion thereof may be printed or otherwise reproduced in any material form whatsoever without the author's prior written permission.