<ul data-eligibleForWebStory="true">Mechanistic PDE Networks is a model for discovering governing partial differential equations from data.It represents spatiotemporal data as space-time dependent linear partial differential equations in neural network hidden representations.The PDEs represented are solved and decoded for specific tasks, expressing spatiotemporal dynamics in data in neural network hidden space.Solving the PDE representations in a compute and memory-efficient manner is a key challenge.A native, GPU-capable, parallel, sparse, and differentiable multigrid solver is developed for linear PDEs within Mechanistic PDE Networks.This solver acts as a module to handle linear PDEs efficiently.The architecture can discover nonlinear PDEs in complex scenarios while being robust to noise, leveraging the PDE solver.PDE discovery is validated on various equations including reaction-diffusion and Navier-Stokes equations.