Despite the fact that the Internet has been in existence for nearly thirty years, it was never able to achieve quite the mass popularity that it has seen since the introduction of the World Wide Web. A large part of this phenomenon must be attributed to the effective use of multimedia techniques in web pages. While multimedia has a fascination to most who surf the web, it is a certainly a great boon to the field of chemistry. Where chemists once were confined to looking at static, two-dimensional images of molecular structures on the printed page, they may now exchange structure files over the web that can be viewed in three dimensions. One of the first tools for viewing structure files, RasMol, is still in use today, owing in large part to its ability to display well-rendered images of structures, as well as the fact that it has a sophisticated command structure. Within RasMol’s command-line interface, one can obtain geometry information on a molecule, including bond lengths, bond angles, and dihedral (torsion) angles. Use of the command-line interface, however, is not always intuitively obvious to the casual user, and so Berkeley-enhanced RasMol was developed, which offers a control panel for interpreting molecular geometry. (Both of these helper applications were reviewed in the second installment of this column.)
Thomas Gardner (Tue,) studied this question.