How to represent a 3D model of cocaine?
While I do not think that cocaine is a particularly interesting molecule, the crystal structure has been reported in Ronald J. Hrynchuk, Richard J. Barton, and Beverley E. Robertson, Can. J. Chem., 1983, 61, 481. There is also an open access paper of the XII IUCr Congress available, R. D. Hrynchuk, R. J. Barton and B. E. Robertson, Acta Cryst A, 1981, A37, C72. The crystal structure file has been deposited to ccdc.cam.ac.uk and can be downloaded free of charge. However, as far as I can see, it does only contain the information about the space group, etc, but no atomic co-ordinates.

However, the hydrochloride structure has also been reported in E. J. Gabe and W. H. Barnes, Acta Cryst., 1963, 16, 796-801. And the cif file can be also obtained at ccdc.cam.ac.uk.

I did a quick calculation on this geometry on the DF-BP86/def2-SVP level of theory, the plain xyz coordinates are attached at the end of this post. You can open them with molecular viewers such as Avogadro to create your own model.

The following, however, has been produced with the commercial ChemCraft program.


I do not know how far you want to go with your presentation, there are some pictures on wikipedia. I can also recommend checking the record of it on ChemSpider.



Geometry of cocaine hydrochloride:

symmetry c1
Cl      -2.051693000     -0.493009000      4.153090000
C       -2.451519000     -3.565091000      6.602382000
C       -6.214292000      1.164927000      8.772468000
C       -7.187531000      2.140573000      9.037661000
C       -8.160694000      1.917991000     10.029303000
C       -8.167271000      0.711328000     10.754343000
C       -7.200746000     -0.269358000     10.489848000
C       -4.535361000     -2.199809000      5.904903000
C       -4.965503000     -2.410764000      3.577976000
C       -0.472992000     -3.311748000      5.082266000
C       -3.681531000     -2.746076000      7.063993000
C       -3.208615000     -1.681350000      8.100725000
C       -1.959949000     -0.929634000      7.627840000
C       -0.886578000     -1.913758000      7.125382000
C       -0.580604000     -3.058883000      8.128726000
C       -1.633721000     -4.157723000      7.786625000
C       -5.209882000     -1.120147000      9.257751000
C       -6.215633000     -0.043947000      9.503197000
H       -2.776079000     -4.325870000      5.870251000
H       -1.141638000     -5.101415000      7.477122000
H       -5.458897000      1.318599000      7.989093000
H       -7.190344000      3.080452000      8.463274000
H       -8.921920000      2.687588000     10.235464000
H       -8.932096000      0.535630000     11.527409000
H       -7.186414000     -1.224606000     11.036739000
H       -4.915209000     -3.233215000      2.840991000
H       -4.408859000     -1.522439000      3.213266000
H       -6.015572000     -2.140911000      3.803492000
H        0.202195000     -3.979332000      5.655364000
H       -4.361351000     -3.437105000      7.610613000
H       -1.009855000     -3.900141000      4.313786000
H        0.111577000     -2.526413000      4.564425000
H       -2.986886000     -2.247300000      9.031392000
H       -2.216795000     -0.241161000      6.793930000
H       -1.551394000     -0.325210000      8.463897000
H        0.011514000     -1.355303000      6.795935000
H        0.453167000     -3.437387000      7.998115000
H       -0.655253000     -2.701279000      9.175171000
H       -2.290875000     -4.410651000      8.642544000
N       -1.471722000     -2.634200000      5.937688000
O       -4.202728000     -0.704253000      8.439562000
O       -5.256578000     -2.245544000      9.737495000
O       -5.375360000     -1.329144000      6.012186000
O       -4.299429000     -2.894414000      4.763398000
H       -1.903686000     -1.736871000      5.153339000