The Opacity Project, Vol. 1 (Opacity Project)

The Opacity Project, Vol. 1 was published in 1995 as the first comprehensive documentation of a collaborative international research endeavor that began in the 1980s. The project was conceived to calculate accurate atomic data—specifically photoionization cross-sections and oscillator strengths—for a wide range of astrophysically important elements. These data were essential for refining models of stellar interiors, atmospheres, and the opacity of stellar matter, which had remained significant sources of uncertainty in theoretical astrophysics.

The volume serves as a technical record of the massive computational undertaking led by a team of physicists from institutions across the globe, including the Queen's University of Belfast, University College London, and various sites in the United States and France. Published by Taylor & Francis, the work is notable for its rigorous methodology and the application of the R-matrix method to solve complex quantum mechanical equations. It was received by the scientific community as a foundational reference tool that significantly improved the accuracy of stellar opacity calculations for decades to follow.