Hi After getting the conformations as *.sdf (or *.pdb) files with Macromodel (from Shroedinger) and/or Vconf(VeraChem) I use Chimera to add missing H's and add charges with amber 99. After these steps are completed, I split the sdf conformations-file into single *.mol2 files. All works fine except for the last step, that changes a single bond into a double bond in each molecule. I am correcting this manualy opening the *.mol2 file with Texd editors and changing the double bond into single bond the the benzene rings. Opening a chosen conformation from the *.sdf file it looks correct.So, the problem happens during conversion/splitting process. Question: How can this arbitrary bond change be avoided? Attached zip file with *.mol2 examples of one compound after splitting process. Thank you Regards Bruno