As anyone who’s written a paper for chemistry class or journal publication knows, spelling “errors” quickly become so numerous that you just ignore them. They’re not really errors, of course, just technical words that Microsoft’s standard dictionary doesn’t include. This is problematic for at least two reasons. One, I tend to gloss over the many, many squiggly red lines and therefore not notice actual spelling errors that have been made. Two, the standard spell checker cannot differentiate between correctly-spelled technical words and misspelled technical words. Thus, all technical words come back as misspelled whether or not they actually are misspelled.

Around this time last year (end of 2007), I was looking for a solution to this problem. I wanted to download a free “custom dictionary” to upload to my word processor to recognize all the words that were correctly spelled, but not recognized by the standard dictionary. Surprisingly, I couldn’t find one. I found several scientific spell check programs, but they are all for-pay versions. I wasn’t interested.

So I set out to create my own chemistry dictionary. I finished it up at the beginning of February (2008), and it was hosted at Sciencebase with thanks to David Bradley (read the post regarding the original release here). The dictionary was relatively small, containing some 18,000 words. But it helped a lot.

Through David, I was introduced to Antony Williams from chemspider.com. I met with him one afternoon in February, and he agreed to release his database of 1.3 million identifiers for me to integrate into the next upgrade. (Update: read Tony’s writeup here)

It took me a while, but the upgrade is complete and ready for release.  Click here to download the zipped chemistry dictionary file.  The 1.3 million identifiers were distilled down to around 102,000 additional words for the dictionary file (more on that in a separate post here).  This upgrade bumps the dictionary from 18,000 words to ~104,000 words.

Administrivia: The dictionary is licensed under the Creative Commons Attribution 3.0 License.  To figure out what that means, click here.  The dictionary is compatible for Microsoft Office (Windows or Mac), and  Open Office (Windows or Linux).  The install file includes instructions for upgrading old versions and installing it for the first time.  The dictionary should be useful for all chemists.  However, I am an organic chemist.  Thus, the dictionary was created from an organic chemist’s mindset.  It will probably be most useful for organic chemists.

Now, I can’t guarantee that the dictionary is perfect. If you have comments, questions, or suggestions, you can leave them in the comments or email me at chemdictionary – at – gmail – dot – com. If you notice a word not in the dictionary that you’d like to see added, you can enter below it in the form that Mitch made for me. (Thanks, Mitch) I’ll review it and consider it for the next upgrade.

***UPDATE (1/22/09)***

1) Several people have emailed me saying they are experiencing some problems integrating the dictionary file with Microsoft Word on a Mac.  Here is a useful workaround:

Open the dictionary file through Microsoft Word (open Word, then goto Open File and change the file type to All Files).  With the dictionary file open, select “Save As.”  One of the “File Type” options to which the file can be saved is a custom dictionary file.  Save the document as a dictionary file with a novel file name.  Then follow the instructions in the install file to add on this new dictionary file.

2) 2 people have independently (and most kindly) formatted the dictionary file for integration into iWork for Macs (OS X only, I believe).  I don’t have a Mac, so I have no idea what that is.  But if two people went out of their way to reformat the dictionary file for it and sent the file to me unsolicited, then it must be good.  Here it is (zip file).  This does not replace the dictionary file for Microsoft Word on a Mac.  You will need to install both files if you use Microsoft Word and iWork.  If you have already created a custom dictionary for iWork, you will need to append this dictionary file to the end of your current custom dictionary.  Here are the install instructions:

If you don’t have a custom dictionary:
Go to: ~/Library/Spelling
copy the file “en” in this location
Log out and then log back in.

if you have a custom dictionary already:
Go to: ~/Library/Spelling
paste the content of chem-dic2:en into ~/Library/Spelling/en using an advanced text editor (i.e. TextWrangler)
Log out and then log back in.

***UPDATE 2 (2/2/09)***

1) Read the article I wrote for the inaugural issue of the ChemSpider Journal of Chemistry here.
2) Read the coverage in the Digital Briefs of C&E News (Subscription Required) here.