You're looking at StableBuild's Deleted PyPI mirror - where we index all deleted packages from the Python package registry.

extinction-coeffcient
1.1

This version was deleted from PyPI around 2023-10-14. Installing fails with:
$ pip3 install extinction-coeffcient==1.1 ERROR: Could not find a version that satisfies the requirement extinction-coeffcient==1.1
View other deleted versions of extinction-coeffcient

Install through StableBuild

You can install this package from StableBuild's PyPI snapshots from before the version was deleted:
pip3 install \ -i https://YOUR_API_KEY.pypimirror.stablebuild.com/2023-10-13/ \ extinction-coeffcient==1.1
Sign up for StableBuild to get an API key (it's free and takes <60 seconds!)

Or, download files manually

And install manually via pip:
extinction_coeffcient-1.1-py3-none-any.whl (7.5KB)
extinction_coeffcient-1.1.tar.gz (6.5KB)