5d transition metal oxides exhibit a wide range of exotic properties including spin orbit assisted Mott insulator, spin Hall effect and spin liquid and hold therefore a huge potential for future spintronic applications. Spin orbit coupling (SOC) is the driving mechanism behind all such exotic properties and states. For this reason understanding the role of SOC is key to understanding a wide range of physical phenomena and guiding their potential applications in technology. We have investigated the electronic band structure of the prototype binary iridate IrO2 by high resolution angle resolved photoemission spectroscopy. Our data are compatible with avoided crossing at the high-symmetry, hexatruple point (HP) along the G- Z direction in the Brillouin zone (BZ). This finding is supported with our density functional theory (DFT) calculations, and consistent with the recently proposed Dirac nodal lines (DNLs) by Sun et al. .
 Y. Sun, Y. Zhang, C.-X. Liu, C. Felser, B. Yan, Dirac nodal lines and induced spin Hall effect in metallic rutile oxides. arXiv:1701.09089 [cond-mat.mtrl-sci] (2017)