CCL: MOPAC2009, new release, optimizes up to 15,000 atoms

MOPAC2009, new release, optimizes up to 15,000 atoms

The ability to model enzyme reactions, optimize whole proteins, segments of DNA, and other large systems is now available with the newly released MOPAC2009.

Conventional semiempirical quantum chemistry scales in both time and memory usage as the third power (cube) of the number of atoms, which sets the practical limit to about 1,000 atoms.  The linear scaling algorithm, MOZYME, now integrated into MOPAC2009, extends the size limit for geometry optimization to about 15,000 atoms, and for SCF to 18,000 atoms, with dramatic increases in computational speed for any molecule larger than about 100 atoms.  With MOZYME, a molecule of 1,000 atoms runs about 60 times faster and uses only 7% of the memory when compared to conventional MOPAC. 

The keyword, MOZYME, works with most MOPAC functionality, including the new PM6 method which was parameterized primarily for biochemical systems.  MOPAC2009 is still free for academic non-profit use.  For further information please see:

David Gallagher