@article{121boykin2001, author = "Timothy Boykin and R. Bowen and Gerhard Klimeck", title = "Electromagnetic coupling and gauge invariance in the empirical tight-binding method", journal = "Physical Review B", year = "2001", volume = "63", number = "24", note = "Physical Review B, Vol 63, pg. 245314 (2001);doi: 10.1103/PhysRevB.63.245314", url = "https://engineering.purdue.edu/gekcogrp/publications/pubs_src/DOC121_e245314.pdf", }