The LG dispersion correction was implemented following the paper “ReaxFF-lg: Correction of the ReaxFF Reactive Force Field for London Dispersion, with Applications to the Equations of State for Energetic Materials” by Liu et al. J. Phys. Chem. A, 2011, 115 (40), pp 11016–11022, http://dx.doi.org/10.1021/jp201599t
The LG dispersion correction is turned on when using a suitable forcefield, which is recognized by the “[ lgDispersion=1 ]” key in the file header.