How Can You Specify An Arbitrary Wall-Particle Potential Via the Fix/Wall Function?

I am interested in simulating adsorbates bound to a surface with a very specific 3D potential obtained from DFT. I was therefore wondering if there is a way to input either a grid-based or analytic form specifying this interaction between a wall and a particle. I have found grid-based ways of inputting pair potentials in the manual using pair styles. Is there a similar way to specify wall-particle potentials? Any advice would be greatly appreciated!

Brenda Rubenstein

Fix addforce can apply atom style variables. So if you can express your wall potential in a position based function, it might be applicable.