Millam99

J. M. Millam, V. Bakken, W. Chen, W. L. Hase, and H. B. Schlegel, “Ab initio classical trajectories on the Born-Oppenheimer Surface: Hessian-Based Integrators using Fifth Order Polynomial and Rational Function Fits,” J. Chem. Phys., 111 (1999) 3800-05. DOI: 10.1063/1.480037