Re: methane dimer



 I had written:
 >
 > Can anyone tell me the experimental CC distance in methane dimer, and the
 > binding energy of the dimer relative to the individual molecules?
 Literature
 > refs, if you can easily lay your hands on them, are also much appreciated.
 > Thanks,
 >
 > Alan Shusterman
 Here is a summary of the replies that I received (the order of the replies is
 not significant).  Thanks for all of your help.
 Alan
 Department of Chemistry
 Reed College
 Portland, OR
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 As far as I know there is no experimental structure of the methane dimer in the
 gas phase available ( It would be a very ambitious experiment !).  But I have
 at least 2 experimental papers:
 Baflie, Ubaldo; Ulivi, Lorenzo; Zoppi, Marco; Barocchi, Fabrizio;
 Frommhold, Lothar.
 Interaction-induced light scattering by gaseous methane: the bound dimer
 contribution (CH4)2.
 Phys. Rev. A:  At., Mol., Opt. Phys. (1994), 50(2-A), 1172-7
 Prengel, Alex T., Jr.
 Raman scattering from colliding molecules and van der Waals dimers in gaseous
 methane and argon.
 (1976) 137 pp.  Avail.: Xerox Univ. Microfilms, Ann Arbor, Mich.,
 Order No. 76-25,319. From: Diss. Abstr. Int. B 1976, 37(5), 2343
 And a lot of theoretical papers, e.g. :
 Tetzger, Thomas G.; Ferguson, David M.; Glauser, William A.
 A computational analysis of interaction energies in methane and neopentane
 dimer systems.
 J. Comput. Chem. (1997), 18(1), 70-79
 Yin, Daxu; MacKerell, Alexander D. Jr.
 Combined ab initio/empirical approach for the optimization of lennard-jones
 parameters.
 Book of Abstracts, 210th ACS National Meeting, Chicago, IL, August 20-24
 (1995),Issue Pt. 1, COMP-153 Publisher: American Chemical Society,
 Washington, D. C.
 Nagy, Jeno; Weaver, Donald F.; Smith, Vedene H., Jr.
 Ab initio methane dimer intermolecular potentials.
 Mol. Phys. (1995), 85(6), 1179-92
 Nagy, Jenoe; Weaver, Donald F.; Smith, Vedene H., Jr.
 A Comprehensive Study of Alkane Nonbonded Empirical Force Fields. Suggestions
 for Improved Parameter Sets.
 J. Phys. Chem. (1995), 99(20), 8058-65
 Nagy, Jeno; Smith, Vedene H., Jr.; Weaver, Donald F.
 Calculation of second virial coefficients of alkanes with the MM2 and MM3 force
 fields.
 Mol. Phys. (1994), 81(5), 1039-47
 Tsuzuki, Seiji; Uchimaru, Tadafumi; Tanabe, Kazutoshi; Kuwajima, Satoru.
 Refinement of Nonbonding Interaction Potential Parameters for Methane on the
 Basis of the Pair Potential Obtained by MP3/6-311G(3d,3p)-Level ab Initio
 Molecular Orbital Calculations: The Anisotropy of H/H Interaction.
 J. Phys. Chem. (1994), 98(7), 1830-3
 Novoa, Juan J.; Whangbo, Myung Hwan; Williams, Jack M.
 Interaction energies associated with short intermolecular contacts of C-H
 bonds.II.Ab initio computational study of the C-H...H-C interactions in methane
 dimer.
 J. Chem. Phys. (1991), 94(7), 4835-41
 Tsuzuki, Seiji; Tanabe, Kazutoshi.
 Basis set effects on the intermolecular interaction energies of methane dimers
 obtained by the Moeller-Plesset perturbation theory calculation.
 J. Phys. Chem. (1991), 95(6), 2272-8
 Szczesniak, M. M.; Chalasinski, G.; Cybulski, S. M.; Scheiner, S.
 Intermolecular potential of the methane dimer and trimer.
 J. Chem. Phys. (1990), 93(6), 4243-53
 Williams, Donald E.; Craycroft, David J.
 Nonbonded hydrogen...hydrogen repulsion energy from ab initio SCF calculations
 of methane, ammonia, water, and methanol dimers.
 J. Phys. Chem. (1987), 91(25), 6365-73
 Kolos, W.; Ranghino, G.; Clementi, E.; Novaro, O.
 Interaction of methane molecules.
 Int. J. Quantum Chem. (1980), 17(3), 429-48
 Hope this helps,
 Ciao
 Heinz
 --
 Dr. Heinz Schiffer		Phone   ++49-69-305-2330
 Hoechst CR&T			Fax     ++49-69-305-81162
 Scientific Computing, G864	Email   schiffer # - at - # h1tw0036.hoechst.com
 65926 Frankfurt am Main		        schiffer # - at - # msmwia.hoechst.com
 ----------------------------------------
 A C-C distance of 3.88 A is reported in
 G. P. Matthews and E. B. Smith, Mol. Phys. 32 (1976) 1719
 Good luck,
 Ole Swang
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 This may not be very helpful, but in the book "Molecular Theory of Gases
 and
 Liquids" by Hirschfelder, Curtis, and Bird (1954) they list constants for
 the
 Lennard-Jones potential determined from second virial coefficients. I would
 expect the equilibrium distance to be overestimated this way and the well depth
 to be underestimated. They list for CH4 :
 epsilon (the well depth) 148.2 K
 sigma 3.817 Angstrom
 (the minimum is at 2^(1/6) sigma or 4.284 Angstrom.
 Good Luck
 Dr. Russell D. Johnson III
 Research Chemist
 Physical and Chemical Properties Division
 National Institute of Standards and Technology
 Gaithersburg, MD 20899
 voice 301+975-2513     fax  301+975-3670
 email: russell.johnson # - at - # nist.gov
 ----------------------------------------
 For a nice thoeretical study done with pretty high level MO calculations and a
 large number of orientations, etc., see:
 J. Chem. Phys., 93, 4243-4253, 1990
 Hope this helps,
 Jay Ponder
 --------
 Jay W. Ponder
 Phone:	(314) 362-4195
 Biochemistry, Box 8231
 Fax:	(314) 362-7183
 Washington University Medical School
 660 South Euclid Avenue
 Email:	ponder # - at - # dasher.wustl.edu
 St. Louis, Missouri 63110  USA
 WWW:	http://dasher.wustl.edu/
 ----------------------------------------
 The following reference may be of some use:
 Journal of Computational Chemistry
 Volume 18 No. 1  p 70-79  (1997)
 Good luck,
 Tom Metzger
 metzger # - at - # mnb.nida.nih.gov