A deterministic global optimization algorithm is introduced for locating global. minimum potential energy molecular conformations. The proposed branch and bound type algorithm attains finite epsilon-convergence to the global minimum through the successive refinement of converging lower and upper bounds on the solution. These bounds are obtained through a novel convex lowering bounding of the total potential function and the subsequent solution of a series of nonlinear convex optimization problems; The minimization of the total potential energy function is performed on an independent set of internal coordinates involving only dihedral angles. A number of example problems illustrate the proposed approach.