DYNAMO is a library of Fortran 90 modules that has been designed for the simulation of molecular systems using molecular mechanical (MM) and hybrid quantum mechanical (QM)/MM potential energy functions.

DYNAMO is a library of Fortran 90 modules that has been designed for the simulation of molecular systems using molecular mechanical (MM) and hybrid quantum mechanical (QM)/MM potential energy functions.

The Dynamo module library has been developed for the simulation of molecular systems using hybrid quantum mechanical (QM) and molecular mechanical (MM) potentials. Dynamo is not a program package but is a library of Fortran 90 modules that can be employed by those interested in writing their own programs for performing molecular simulations. The library supports a range of different types of molecular calculation including geometry optimizations, reaction-path determinations and molecular dynamics and Monte Carlo simulations. This article outlines the general structure and capabilities of the library and describes in detail Dynamo's semiempirical QM/MM hybrid potential. Results are presented to indicate three particular aspects of this implementation - the handling of long-range nonbonding interactions, the nature of the boundary between the quantum mechanical and molecular mechanical atoms and how to perform path-integral hybrid-potential molecular dynamics simulations.