T(K) cross sect. at 220.67 nm 1660 1.97e-19 1700 2.11e-19 1755 2.32e-19 1800 2.49e-19 1850 2.69e-19 1900 2.90e-19 1950 3.12e-19 2000 3.34e-19 2030 3.47e-19