Local order parameters for use in driving homogeneous ice nucleation   with all-atom models of water
  We present a local order parameter based on the standard Steinhardt-Ten Wolde approach that is capable both of tracking and of driving homogeneous ice nucleation in simulations of all-atom models of water. We demonstrate that it is capable of forcing the growth of ice nuclei in supercooled liquid water simulated using the TIP4P/2005 model using overbiassed umbrella sampling Monte Carlo simulations. However, even with such an order parameter, the dynamics of ice growth in deeply supercooled liquid water in all-atom models of water are shown to be very slow, and so the computation of free energy landscapes and nucleation rates remains extremely challenging. 
Aleks Reinhardt, Jonathan P. K. Doye, Eva G. Noya, Carlos Vega
cond-mat.stat-mech physics.chem-ph