Hoomd-Blue Long-Range Electrostatics PPPM in 2D Box

[anisha-yeddanapudi]

Hi,

I'm trying to simulation charged patchy particles as rigid bodies in a 2D box. In addition to interacting with LJ and the patches interacting with the Morse potential. When I attempted to introduce hoomd.md.long_range.pppm.make_pppm_coulomb_forces in the box I'm getting a ZeroDivisionError. I was wondering if Hoomd's PPPM supports 2D, as when I run a simpler model in 3D the PPPM seems to work properly. Additionally, for this implementation the Ewald seems to work fine, it's only when I proceed to implement the Coloumb interactions.

Let me know your thoughts.

frame.configuration.box = [L, L, 0, 0, 0, 0]
frame.particles.charge = [-1]* N_particles

ewald, coulomb = hoomd.md.long_range.pppm.make_pppm_coulomb_forces(
    nlist=cell,
    resolution=(64, 64, 64),
    order=4,
    r_cut=2.5
)

integrator.forces.append(ewald)
integrator.forces.append(coulomb)
integrator.forces.append(lj)

Additionally, if 2D simulations are not supported, please let me know any recommendations for implmeneting the Coulomb interaction between two different particle types 'A' and 'B'.

Thanks.

[joaander]

I do not know if PPPM should support 2D or not. If screened charges are appropriate for your model, use the Yukawa pair potential.

[anisha-yeddanapudi]

Thank you so much!