Date of Award

Spring 2007

Document Type

Restricted Thesis

Terms of Use

© 2007 George Hang. All rights reserved. Access to this work is restricted to users within the Swarthmore College network and may only be used for non-commercial, educational, and research purposes. Sharing with users outside of the Swarthmore College network is expressly prohibited. For all other uses, including reproduction and distribution, please contact the copyright holder.

Degree Name

Bachelor of Arts


Physics & Astronomy Department

First Advisor

Amy Lisa Graves


In this thesis, the phenomenon of tunnel splitting in quantum hindered rotors is examined in detail. The mathematical basis for Lanczos methods, a family of algorithms efficient for finding extremal eigenvalues in a sparse Hermitian matrix, is investigated. An implementation of the block Lanczos method with total orthogonalization in FORTRAN 77 is upgraded and redesigned in modern FORTRAN 95. Benchmarking against analytical solutions and literature values suggest that the code is robust and the computational results show quantitative tunnel splitting results that match the qualitative predictions from quantum theory.