Athanor by arbastro
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How to add charges, radicals and lone pairs

Press Q for the Charges tool, pick plus (+), minus (-), lone pair (L), radical, diradical, delta plus or delta minus, and click the atom. clear takes every mark off an atom.

Steps

  1. Press Q for the Charges tool. The row above the toolbar shows what it can add: plus, minus, circled plus, circled minus, lone pair, radical, diradical, delta plus, delta minus and clear.

    The Charges tool's options, from plus and minus to delta charges and clear.The Charges tool's options, from plus and minus to delta charges and clear.

  2. Pick one. + is plus, - is minus and L is lone pair.

  3. Click the atom. Click again to add another of the same, for example a second lone pair.

  4. To take the marks off an atom, pick clear and click it.

Acetate ion, with a negative charge and lone pairs on its oxygen.Acetate ion, with a negative charge and lone pairs on its oxygen.

Tip

No need to switch tools for a charge: point at any atom and press + or -.

Partial charges

delta plus and delta minus draw δ+ and δ− beside an atom, the usual way to show a polar bond such as C=O.

Drawing basicsHow to change an atom to another elementPoint at an atom and press its letter (C, N, O, S, P, F, I, H, B or K). For anything else, point and press Enter to type a label such as Cl, Br or OMe, or select atoms and choose an element in View › Periodic table.Atoms, bonds and ringsHow to show R and S, E and Z labelsTurn on View › Show stereochemistry. Each stereocenter gets R or S and each stereo double bond E or Z, worked out from the CIP priority rules and updated as you draw.Keyboard shortcutsKeyboard shortcutsPress ? in a document for the Controls cheat sheet, or Ctrl+K and search for a command to see its shortcut. Every shortcut can be changed in Settings › Shortcuts. On a Mac, Ctrl is Cmd.

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Last updated Nov 12, 2026