Reply To: Chemistry arrows with horizontal lines below them
Ah, now I see the image you sent. These are valence arrows. The current chemistry code doesn't discuss these in detail and may suggest that they be drawn. Transcribers have come up with different solutions to this problem, and the BANA chemistry committee is working on a recommendation which you may use in your transcription. Describe the symbols in a TN. You may use just the < symbol for the up-pointing valence arrow and just the % symbol for the down-pointing valence arrow. These symbols are to be used only in the context of valence arrows depicted in orbital diagrams. It is not necessary to indicate that the arrowheads are barbed--this is just a print style.
In your book, the arrow pairs are grouped with underlining. Show the grouping by inserting one space between pairs. When only the up arrow appears, the general omission symbol of the Nemeth Code is used to show the absence of the down-pointing valence arrow within the pair. Place element SYMBOLS or orbital level notation as column headings, leaving only one space between columns. I have attached a suggested solution to your example. This should work nicely for you.
Lindy