MPQC is the Massively Parallel Quantum Chemistry Program. It computes properties of atoms and molecules from first principles using the time independent Schrodinger equation. It runs on a wide range of architectures ranging from individual workstations to symmetric multiprocessors to massively parallel computers. Its design is object oriented, using the C++ programming language. Capabilities o Closed shell and general restricted open shell Hartree-Fock energies and gradients o Second order open shell perturbation theory (OPT2[2]) and Z-averaged perturbation theory (ZAPT2) energies. o Second order closed shell Moller-Plesset perturbation theory energies and gradients. o Robust internal coordinate geometry optimizer that efficiently optimizes molecules with many degrees of freedom. You can also validate your mpqc binaries when you employ other settings by: % make validate >& validate.log & (it may take few days, though) For details, please see file:///usr/local/share/doc/mpqc/hierarchy.html or http://www.mpqc.org/mpqc-html/mpqcval.html