Advanced guides# Defining Custom Models Commonalities Using Flax Linen Using Jax/Stax Using Haiku Overriding defaults in NetKet NetKet Architecture: Multiple Dispatch Defining Custom Preconditioners The preconditioner interface Defining Custom Observables and Operators Defining a custom zero operator Defining an operator from scratch Defining an operator the easy way Comparison of the two approaches Custom Hilbert Space Constraints Built-in Constraints Overview Interface Requirements Advanced Patterns Integration with Variational States See Also