science-softCon uv/vis+ photochemistry database; www.photochemistry.org; (C) science-softCon 2019 Substance: methane Other Names: Formula: CH4 CAS-No.: 74-82-8 Study: vuv absorption spectrum Authors: H. Sun, G.L. Weissler Title: Absorption cross sections of methane and ammonia in the vacuum ultraviolet Journal/Source: J. Chem. Phys., 23, 1160-1164, (1955); doi:10.1063/1.1742205 Data: table, diagram Energy/Wavelength range: ~ 38 - 130 nm Resolution: Temperature: 295 K Temperature dependence: Pressure/Concentration: Phase: gas pH: Comments: For methane 85 wavelengths were measured. From sigma = 14 Mb (1 Mb = 10-18 cm2) at 1300 A, the absorption first increased slowly and then rose more rapidly to a maximum of sigma = 56 Mb at 960 ± 278 A corresponding to the first ionization potential of methane. The absorption then decreased gradually to 14 Mb at 374 A. Author to whom correspondence should be addressed: (e-mail address):