dat and remove the Tv and the entire mersx11 command line near the bottom and

Dat and remove the tv and the entire mersx11 command

This preview shows page 22 - 26 out of 26 pages.

Using a text editor, open the “name-of-file.dat” and remove the “Tv” and the entire “mers=(x,1,1)” command line (near the bottom and top of the line) and change the ghost atom (“xx”) back into a hydrogen, H, atom (or what ever atom one used) to be viewed with Hyperchem Pro 5.1. Simply rename this modified file and save the file out as a *.zmt file and check the structure by opening it back into the Hyperchem 5.1 Pro (see figure 2.2 and Appendix F). As shown in figure 2.2, the program was able to generate the repeating structure with all its atoms using the original unit cell after running the job on makpol.exe.
Image of page 22
57 mers(2,1,1) unit cell from C 60 mers(3,1,1) unit cell from C 60 mers(4,1,1) unit cell from C 60 Figure 2.2: Checking the “make file” after running in makpol.exe to generate the polymer of unit cells. The unit cell was taken from C 60 and (2,1,1), (3,1,1), and (4,1,1) were the repeating unit used to generate a SWNT, C 120 , C 180 , and C 240 , structures consisting of 120, 180, and 240 carbon atoms.
Image of page 23
58 2.5.1 The types of jobs done using MOPAC 2000 on the [5,5] armchair SWNT Once the files have been checked, the following calculations are performed using the MOPAC 2000 utility package: 1) a single-point (SP) with no PBC enforced, 2) a SP calculation with PBC enforced, and 3) optimize the molecule with PBC enforced. All jobs determined the heat of formation for each molecule. Of the three jobs done, the most important is 3) imposing PBC while optimizing the molecule. These optimized PBC structures would then be used to determine: 1) the repeating unit cell, 2) which C n [5,5] armchair SWNT belongs to the repeating unit, and 3) how many diameter(s) and carbon-carbon bond distance(s) are there for an infinite length of the [5,5] armchair SWNT at bulk.
Image of page 24
59 REFERENCES FOR CHAPTER 2 1. Young, D.C., Computational Chemistry, A Practical Guide for Applying Techniques to Real World Problems . 2001, New York, Chichester, Toronto: A John Wiley & Sons, Inc. 2. Cramer, C.J., Essentials of Computational Chemistry, Theories and Models . 2002 ed. 2002, Southern Gate, Chichester, West Sussex: John Wiley & Sons, LTD. 3. Atkins, P.W. and Friedman, R.S., Molecular Quantum Mechanics . 3rd ed. 1996, Oxford: Oxford University Press Inc. 291-292. 4. Dunning, T.H., J. Chem. Phys., 1989. 90 : p. 1007-1023. 5. Chase, M.W.J., NIST-JANAF Thermochemical Tables G=on . 1998, J. Phys. Chem. Ref. Data, Monograph 9. 6. Wagman, D.D., Kilpatrick, J.E., Pitzer, K.S., and Rossini, F.D., Heats, equilibrium constants, and free energies of formation of the acetylene hydrocarbons through the pentynes, to 1,500oK. J. Res. NBS, 1945. 35 : p. 467- 96. 7. Curtiss, L.A., Raghavachari, K., Redfern, P.C., Rassolov, V., and Pople, J.A., Gaussian-3 (G3) theory for molecules containing first and second-row atoms. Journal of Chemical Physics, 1998. 109 (18): p. 7764-7776. 8. Stewart, J.J.P., Optimization of Parameters for Semiempirical Methods II. Applications. Journal of Computational Chemistry, 1989. 10 (2): p. 221-64.
Image of page 25
Image of page 26

You've reached the end of your free preview.

Want to read all 26 pages?

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture

Stuck? We have tutors online 24/7 who can help you get unstuck.
A+ icon
Ask Expert Tutors You can ask You can ask You can ask (will expire )
Answers in as fast as 15 minutes