I am trying to model adsorption of water on metal surfaces for electrochemical simulations. There is a particular force field I want (Siepmann et al. J. Chem. Phys. 102 (1), 1 January 1995) which involves computing an angle force based on water dipole vector relative to the vector normal to the metal surface. The purpose of this term is to rotate the water to face hydrogen-upward.
There is another 3-body term which involves computing a force based on the Metal-Metal to Metal-Oxygen bond angle for each of the adjacent surface metal atoms (so 6 3-body interactions for 111)
Is there a way to do either of these things in LAMMPS without coding a new force field? I thought about using 'fix angle_style table' for the 3-body term but I am not sure how to build a list of surface metal atoms adjacent to the metal which has the adsorbed water molecule.
Thanks for your time.