template<class T>
void OEGeom3DReflectCoord(T *dst, const T *center,
                          const T *r1, const T *r2,
                          const T *rHyd);

This is a template function that takes T* coordinates of a central atom (center) and two r-group atoms (r1 and r2), and performs a reflection around the center-r1-r2 plane for the hydrogen atom (rHyd). The output coordinates are returned within the dst variable.