Finite-Difference and Analytic-Gradient Approaches for Simulating Vibrational Circular Dichroism Using Second-Order Møller-Plesset Perturbation Theory and Configuration Interaction

Vibrational circular dichroism (VCD) is defined as the differential absorption of left- and right-circularly polarized light in the infrared region of the electromagnetic spectrum. Application of this spectroscopy is primarily directed towards the elucidation of molecular absolute configuration. As a result of the complex relationships involved in light-matter interactions, theoretical simulation is required to interpret experimental results. In this work, we focus on improving the accuracy and efficiency of simulating VCD spectra. First, we discuss the effects of the choice of basis set on two chiroptical properties including VCD and Raman optical activity (ROA) with a particular emphasis on property-oriented basis sets. Next, we introduce a finite-difference scheme for computing the atomic axial tensor (AAT), a required quantity for VCD simulation, for the second-order Møller-Plesset perturbation (MP2) theory and configuration interaction with double excitations (CID) electronic structure methods. Finally, we formulate an analytic implementation of the MP2 and configuration interaction including single and double excitations (CISD) AATs.

Name thesis:degree_name

Doctor of Philosophy

Level thesis:degree_level

doctoral

Discipline thesis:degree_discipline

Chemistry

Department dc:contributor.department

Chemistry

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

2025

Author dc:creator

• Shumberger, Brendan Michael

Chair dc:contributor.committeechair

• Crawford, Daniel

Committee members dc:contributor.committeemember

• Mayhall, Nicholas
• Valeyev, Eduard Faritovich
• Welborn, Valerie

• spectroscopy
• vibrational circular dichroism
• electronic structure theory
• perturbation theory
• configuration interaction

Statement dc:rights

• Creative Commons Attribution 4.0 International

Licence dc:rights.uri

• http://creativecommons.org/licenses/by/4.0/

Language dc:language.iso

en

Dc Identifier Other

vt_gsexam:43761

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/132477