## Section: Software

Keywords : quantum chemistry, semi-empirical, simulation, parallelism.

`QC++`

Participants : Olivier Coulaud [ corresponding member ] , François Pellegrini, Gérald Monard.

`QC++` is a Quantum Chemistry software written in C++.
The current version of QC++ supports the semi-empirical
quantum models MNDO, AM1 and PM3. It allows to calculate the energy of
a molecular configuration by some Self Consistent Field (SCF)
algorithms : fixed point, optimal damping and level shifting. It is
also possible to optimize its geometry by using the minimization
algorithms L-BFGS and BFGS.

The major new feature in the version 2.0 is the implementation of
a linear scaling ``*divide and conquer* '' method both in
sequential and parallel to calculate the electronic energy. Several
type of subdomains and strategies to partition a molecule are
available, one of them being based on `Scotch` .