Gary Mallard: The resources needed to do the data evaluation and collection do not really change, whether you are putting data out in an electronic format or in printed format, and so that number is constant and really represents whatever we can find at NIST. In a lot of cases, we have been taking data that we have had for a long time in printed format and just putting it in electronic format. So that is relatively inexpensive and fairly cost effective because it really just takes somebody with good data entry skills to put it in a spreadsheet, and we do a little processing on it.

One person works full time on the database itself. There is a Java applet that displays spectra that can be enlarged. The address is <> and I would urge all of you to go there and try it. A lot of what that one person does is deal with issues on the Web, and we work very hard to make sure that if we display a Greek character it displays on a Sun system, on a Macintosh, and on Windows, and that is a non-trivial exercise. A lot of time is spent in making sure that this is a high-quality product that looks the same on everybody's browser, that the Java applet works the same on everybody's browser, and none of that is easy. So, in that sense there is one person devoted full time just to keeping this thing up on the Web.

The structure of the database is basically a file that is indexed under C-Tree, an available piece of software that is all C code and has been known to compile on more platforms than anything else known to man. We store everything as ASCII, because we feel that when you deal with things like the number of significant figures, you would like to capture that information and not lose it, and so we have some fairly sophisticated algorithms for looking at the number of significant figures. Also, when we convert from kilocalories, which is perhaps what the data was originally entered in, into kilojoules we try to retain all of that information and not have six significant figures of zeroes which aren't significant, but the structure of the database itself is basically just ASCII.

Jack Kay, Drexel University: Are the JANAF thermochemical tables included in this database?

Gary Mallard: Yes, not as tables but as equations in the new format, the Shomate coefficients where there is a 1/T term in the last term.

Robert Cordova, Elf Atochem: I was wondering about the relationship between this and database 19 for structures and properties.

Gary Mallard: What I didn't show you on that form was that in the very beginning we actually had some estimates in the database, and those estimates came out of some of the kind of code that was in the database for structures and properties. We removed all of the estimates. The WebBook really is a kind of evolutionary extension of the structures and properties database. There are a lot more thermochemical data in the WebBook, but the estimation tool that was a part of structures and properties is not there. I think eventually we will put it back, but we just haven't had the resources to do it yet.

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