## Summary Hi, I believe that the formula of [Restricted bending force](<https://manual.gromacs.org/current/reference-manual/functions/bonded-interactions.html#restricted-bending-potential>), Eq. 189, contains the following error. - There should not be factor 2. - There should be a minus sign at the beginning. Also, on the same page, journal information of references (83) and (88) are swapped. (Titles and authors are correct.) Current (incorrect) > 83 M. Bulacu, N. Goga, W. Zhao, G. Rossi, L. Monticelli, X. Periole, D. Tieleman, and S. Marrink, “Improved angle potentials for coarse-grained molecular dynamics simulations,” J. Chem. Phys., 123 [11] (2005). > 88 M. Bulacu and E. van der Giessen, “Effect of bending and torsion rigidity on self-diffusion in polymer melts: A molecular-dynamics study,” JCTC, 9 [8] 3282–3292 (2013). They should be > 83 M. Bulacu, N. Goga, W. Zhao, G. Rossi, L. Monticelli, X. Periole, D. Tieleman, and S. Marrink, “Improved angle potentials for coarse-grained molecular dynamics simulations,” J. Chem. Theory Comput., 9 [8] 3282–3292 (2013). > 88 M. Bulacu and E. van der Giessen, “Effect of bending and torsion rigidity on self-diffusion in polymer melts: A molecular-dynamics study,” J. Chem. Phys., 123 [11] 114901 (2005). ## Additional information This error must have been inherited from the original paper Ref 83 (2013 JCTC). Briefly looking at the code <https://gitlab.com/gromacs/gromacs/-/blob/main/src/gromacs/listed_forces/restcbt.cpp>, it seems the force is correctly calculated without factor 2 (otherwise one would notice this earlier).