Hello OpenBabel Developers, While testing numerical OOP derivatives I found a bug in
forcefield.cpp on line 3741 in function double OBForceField::VectorOOPDerivative(double *pos_i, double *pos_j, double *pos_k, double *pos_l, double *force_i, double *force_j, double *force_k, double *force_l) LINE 3844 VectorSelfMultiply(force_i, (sin_theta/length_ji)); ==================================================== should be replaced by VectorDivide(force_i, (sin_theta * length_ji), force_i); ======================================================== the function to be calculated is given on line 3838 /* i = ((bn + (((-ji + jk * cos_theta) * sin_dl) / sin_theta)) / length_ji) / sin_theta; */ substituting X for (bn + (((-ji + jk * cos_theta) * sin_dl) / sin_theta)) i = ( x / length_ji ) / sin_theta i = x / (length_ji * sin_theta) the same goes for line 3851 VectorSelfMultiply(force_k, (sin_theta/length_ji)); ==================================================== should be replaced by VectorDivide(force_k, (sin_theta * length_jk), force_k); ======================================================== it should fix problems related with OOP calculations Gerd ------------------------------------------------------------------------------ EditLive Enterprise is the world's most technically advanced content authoring tool. Experience the power of Track Changes, Inline Image Editing and ensure content is compliant with Accessibility Checking. http://p.sf.net/sfu/ephox-dev2dev _______________________________________________ OpenBabel-Devel mailing list OpenBabel-Devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/openbabel-devel
