For the purpose of creating a computationally fast and light-weight simulation of charge
drift, diffusion, and collection in the nEXO TPC, a numerical Python package was developed
which implements two different models. The models implemented are: diffusion via fragmentation of a charge cloud into point charges, and diffusion via integration of the idealized
Gaussian distribution across the anode’s charge-collection pads. Both methods are described
in detail, and the latter is compared to a more detailed simulation
