Libint/Description

Libint version 1 ("Libint1") is the old(er) code that supports four-center electron-repulsion (Coulomb) integrals and their first and second geometrical derivatives, as well as four-center integrals that appear in the "old" R12 methods using linear correlation factor. MPQC and CP2K have interfaces to this version of Libint, and Psi has Libint1 embedded. Version 1 is no longer actively developed. Maintenance releases may still appear as necessary.