A new method is presented to extract "optimal" interatomic potentials from first-principles calculations. The method involves fitting the potential to atomic forces from various configurations, including surfaces, clusters, liquids, and crystals at finite temperatures. This approach allows for constructing potentials with accuracy comparable to ab initio methods. The method uses a numerical optimization procedure to match forces from first-principles calculations with those predicted by the potential, minimizing an objective function that includes both force and constraint terms. The potential is defined by a set of single-variable functions derived from atomic coordinates. For example, a glue potential is defined by a pair potential, an atomic density function, and a glue function. The parameters of the potential are determined by minimizing the objective function, which includes terms for force matching and additional constraints. The method is tested on aluminum, where it successfully reconstructs the original potential with high accuracy. The method is effective in obtaining realistic classical potentials with high transferability for systems that can be treated by ab initio calculations. The numerical optimization procedure is well-suited for handling complex analytic forms, including angular-dependent terms, required for realistic modeling of covalent bonds. The method is also useful for comparing different functional forms based on their accuracy in reproducing ab initio forces and for fitting alloys where experimental data is limited. The potential for aluminum was parametrized using 40 parameters, with 14 for the pair potential and 12 for the glue function. The potential was validated against experimental data, showing good agreement for properties such as surface energies, thermal expansion, and melting temperature. The method is expected to be widely applicable for constructing accurate interatomic potentials for a variety of materials.A new method is presented to extract "optimal" interatomic potentials from first-principles calculations. The method involves fitting the potential to atomic forces from various configurations, including surfaces, clusters, liquids, and crystals at finite temperatures. This approach allows for constructing potentials with accuracy comparable to ab initio methods. The method uses a numerical optimization procedure to match forces from first-principles calculations with those predicted by the potential, minimizing an objective function that includes both force and constraint terms. The potential is defined by a set of single-variable functions derived from atomic coordinates. For example, a glue potential is defined by a pair potential, an atomic density function, and a glue function. The parameters of the potential are determined by minimizing the objective function, which includes terms for force matching and additional constraints. The method is tested on aluminum, where it successfully reconstructs the original potential with high accuracy. The method is effective in obtaining realistic classical potentials with high transferability for systems that can be treated by ab initio calculations. The numerical optimization procedure is well-suited for handling complex analytic forms, including angular-dependent terms, required for realistic modeling of covalent bonds. The method is also useful for comparing different functional forms based on their accuracy in reproducing ab initio forces and for fitting alloys where experimental data is limited. The potential for aluminum was parametrized using 40 parameters, with 14 for the pair potential and 12 for the glue function. The potential was validated against experimental data, showing good agreement for properties such as surface energies, thermal expansion, and melting temperature. The method is expected to be widely applicable for constructing accurate interatomic potentials for a variety of materials.