On the optical properties of thin-film vanadium dioxide from the visible to the far infrared, C. Wan, Z. Zhang, D. Woolf, C. M. Hessel, J. Rensburg, J. M. Hensley, Y. Zhao, A. Shahsafi, J. Salman, S. Richter, Y. Sun, M. M. Qazilbash, R. Schmidt-Grund, C. Ronning, S. Ramanathan and M. A. Kats, to appear in Annalen der Physik (arXiv:1901.02517, 2019)