Frequently Asked Questions


Q: Is it possible to replace a part of a molecule with an arbitrary symbol such as X, Y, or R, and then use ACD/Name to name all possible molecules?

A: It is not possible to omit an atom or group and then use an arbitrary symbol with ACD/Name. It is possible, however, to subject a series of several thousand composed molecules in an SDF file with ACD/Name Batch to determine the names.

Q: What do the tildes and underscores in the IUPAC names represent?

A: The insertion of tildes into the name denotes superscripting. (For example; N~2~ indicates the 2 is superscripted on the N.) Subscripting is denoted with underscores (for example; d_4_ in the case of methanol-d4). When using ACD/Name to Structure, these characters must be used for proper structure generation.

Q: How can I have the Name Add-in for ISIS/Draw use the same rule set as ACD/Name.

A: If the freeware is installed, there is no way to change preferences at all. The freeware ACD/Name library (DLL) uses the default 'coded' preferences".

If a commercial package is installed with the ACD/Name Add-in for ISIS/Draw, try the following:

  1. Run ACD/Name to specify the rules of name generation.
  2. Close the program.
  3. Run the REGEDIT.EXE system utility to get access to the Windows registry.
  4. Locate and select the following registry key:

    HKEY_CURRENT_USER\Software\Advanced Chemistry Development (ACD)\NAME.

  5. Export the selected branch to some file.
  6. Expand the selected branch and rename the nested key(s) from "Name" to "NameLib" (for IUPAC Name) and/or from "IndexName" to "IndexNameLib" (for Index Name); if "NameLib" and/or "IndexNameLib" keys already exist, then delete these keys before the renaming procedure.
  7. Now import the branch that was exported in step 5.
  8. Optional; if distributing the same rules to several computers is required, then select the HKEY_CURRENT_USER\Software\Advanced Chemistry Development (ACD)\NAME branch again and export it to some file; use this file to import the branch to the Window registry of other computers.

Q: Can I generate the IUPAC name for cholesterol using Name freeware?

A: No, because Name freeware has a limitation of 50 atoms and 3 rings. To name larger structures, please use ACD/Name.

Q: I receive the error message ‘Structure contains non-supported carbohydrate derivative'.


  1. Open ACD/Name.
  2. Import the structure into the ChemSketch window.
  3. Click the IUPAC Preferences button on the bottom switching bar. The IUPAC Name Generation Preferences window appears.
  4. Switch to the Custom tab.
  5. Unselect the Carbohydrates check box.