CompuServe Messages

pb

    15-Jul-93 08:54:46
Sb: #49645-pb
Fm: Tom Slee [Hypercube] 70761,3021
To: Larry Jones 72370,1001
To load in a structure from crystallographic data, you need to get it into a format that HyperChem can read. I would recomend a HIN file format. ALthough the HIN file can get pretty complicated, it ca also be pretty simple . Here is an example. mol 1 atom 1 – C ** – 0.0 -0.67 0.0 0.0 0 atom 2 – C ** – 0.0 0.67 0.0 0.0 0 endmol This gives you two carbon atoms. You need the -'s and **'s, but can ignore column numbers: it is just white-space separation that matters. The first 0.0 in each line is the charge. The next three numbers are coordinates, and the final 0 is the number of neighbours. To add the bonding information to this, there is a trick. Save the file as a z-matrix and read it in again. The z-matrix reader has a bond-inferring component: not completely reliable, but it makes a good first guess. Then choose "Add hydrogens" under Build to add the hydrogens and you have ethylene. Hope this helps, TOm