(1.5 * r - 2.0) * rvec / rnorm in line 84 of vampnet/vampnet /data_generator.py

[gongshuai0606]

Isn't the gradient (1.5 * r - 2.0) * rvec / rnorm in line 84 of vampnet/vampnet /data_generator.py supposed to be the (1.5 * r**2 - 2.0*r) * rvec / rnorm according to the potential energy function of Protein-folding model "U(r) = 0.5(r-3)^3 - (r-3)^2 for r>3" of paper "VAMPnets for deep learning of molecular kinetics"?