The core function of DMFF is a differentiable molecular force field calculator, the structure of which is represented in Figure . DMFF force field implementations can be divided into two parts: the frontend interfaces and the backend kernels. The DMFF frontend is in charge of model preparation, and is currently designed to resemble the behavior of the OpenMM API. By doing so, we can share the well-established open-source OpenMM ecosystem for the convenient definition of molecular force field. All parameters can be defined in the format of OpenMM force field XML files and a core class named "Hamiltonian" is devised to overload the "ForceField" class in OpenMM. Within the Hamiltonian object, the force field parameters are read and stored in a highly organized and hierarchical data structure.