Importance of polarization in simulations of condensed phase energetic materials

An embedded cluster model is used to estimate the molecular dipole moment o f crystalline dimethylnitramine (DMNA). The electrostatic potential due to the crystal is included in the calculation via the SCREEP (surface charge r epresentation of the electrostatic embedding potential) approach. The resul ting dipole moment for DMNA in the crystalline environment is 6.69 D. This number is more than 40% greater than the gas-phase value and 15% greater th an the estimated dipole moment in the liquid phase, thus providing evidence of a strong polarization effect in condensed phases of DMNA.