A Self-Consistent Field Quantum Hydrodynamic Approach for Molecular Clusters^†

We present a novel self-consistent orbital-free method useful for quantum clusters. The method uses a hydrodynamical approach based on the de Broglie−Bohm description of quantum mechanics to satisfy an orbital-free density functional-like Euler−Lagrange equation for the ground state of the system. In addition, we use an information theoretical approach to obtain the optimal density function derived from a series of statistical sample points in terms of density approximates. These are then used to calculate an approximation to the quantum force in the hydrodynamic description. As a demonstration of the utility and flexibility of the approach, we compute the lowest-energy structures for small rare-glass clusters of argon and neon with 4, 5, 13, and 19 atoms. Extension to more complex systems is straightforward.