<div><img src="data:chemical/x-gamess-input;base64,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" alt="">I have the following simple water MD simulation which outputs positions and velocities at every time step. However I would also like to print the atomic forces at each step, which surely must be computed internally.</div><div><br></div><div>Does anyone know how to do this? Or am I forced to compute the atomic forces in a separate step for each timestep after the simulation?</div><div><br></div><div>Kind Regards</div><div>Tue Boesen<br></div><div>University of British Columbia<br></div>