Figure 3. The methyl-tetrazine moiety is rotated by ~90° to the plane perpendicular to the phenyl group.
However, if desired, the user may specify Cartesian coordinates of any point in space that is a relevant center of the fragments (e.g., the center of the porphyrin ring of a bacteriochlorophyll fragment). The orientation-dependent part can be used to analyze the quality of dipole alignment of molecular fragments.
The software can be used as a tool for time-efficient screening calculations. However, the user has to be aware of the screened point-dipole approximation limitations to ensure that the given method is valid for systems of their choice. For systems where non-dipole contributions are significant, the proposed approximation may be insufficient. Alternatively, other methods beyond those implemented in PyFREC should be used instead.6, 24, 25