[Physics] Comprehensive library of parton density functions

 The PDFLIB package gathers about 100 different sets of Parton Density
 Functions into a comprehensive library in a consistent way. Density functions
 are available for the nucleon, pion and photon. The library also allows the
 calculation of the strong force coupling constant to first or second order
 at a given value of Q-squared.
 .
 Note that in order to compile and link programs against this library, you
 must also install the libpdflib804-2-dev package.