When I using the dynasor for a traditional solid thermoelectric material, all the procedures are similar like the example of Al in the website. We know that Al only has one atom in its primitive cell, so no optical mode for it. In our study, 2 atoms in the primitive cell, and our results show optical mode. Because we do not contain any charge information in the input file, we are not sure whether the result is reasonable, or we want to ask is it possible to obtain the optical phonon mode without charge information?
Im not entirely sure I understand what you mean.
Dynasor only process the atomic positions / velocities in the MD trajectory file. So if MD was run with an interatomic potential including charges, those effects will be captured.
But if you have charged ions in your system and run the MD with e.g. a short-ranged interatomic potential, then the resulting phonon dispersion from dynasor will not include the effect of LO-TO splitting which may affect some of the optical modes at the Gamma point.