Texworks is not finding packages

You need to make sure the texlive packages are at the top of the path list.
Go to Edit->Preferences->Typesetting
Under Paths for TeX and related programs, make sure that /usr/ias/texlive/20XX/bin/x86_64-linux is listed at the top, where 20XX is either 2012 or 2013.
If they are not there, click on the up arrow until they are at the top.
Click on OK