Author:
Kłos Jacek,Tiesinga Eite,Kotochigova Svetlana
Abstract
AbstractThere exist multiple ways to cool neutral molecules. A front runner is the technique of buffer gas cooling, where momentum-changing collisions with abundant cold noble-gas atoms cool the molecules. This approach can, in principle, produce the most diverse samples of cold molecules. We present quantum mechanical and semiclassical calculations of the elastic scattering differential cross sections and rate coefficients of the C60 fullerene with He and Ar noble-gas atoms in order to quantify the effectiveness of buffer gas cooling for this molecule. We also develop new three-dimensional potential energy surfaces for this purpose using dispersion-corrected density functional theory (DFT) with counterpoise correction. The icosahedral anisotropy of the molecular system is reproduced by expanding the potential in terms of symmetry-allowed spherical harmonics. Long-range dispersion coefficients have been computed from frequency dependent polarizabilities of C60 and the noble-gas atoms. We find that the potential of the fullerene with He is about five times shallower than that with Ar. Anisotropic corrections are very weak for both systems and omitted in the quantum scattering calculations giving us a nearly quantitative estimate of elastic scattering observables. Finally, we have computed differential cross sections at the collision energies used in experiments by Han et al. (Chem Phys Lett 235:211, 1995), corrected for the sensitivity of their apparatus, and we find satisfactory agreement for C60 scattering with Ar.
Funder
Air Force Office of Scientific Research
National Science Foundation
National Institute of Standards and Technology
Publisher
Springer Science and Business Media LLC
Reference41 articles.
1. Krätschmer, W., Lamb, L. D., Fostiropoulos, K. & Huffman, D. R. Solid C60: A new form of carbon. Nature 347, 354. https://doi.org/10.1038/347354a0 (1990).
2. Dresselhaus, M., Dresselhaus, G. & Eklund, P. Science of Fullerenes and Carbon Nanotubes (Academic Press, 1996).
3. Kroto, H. W., Heath, J. R., O’Brien, S. C., Curl, R. F. & Smalley, R. E. C60: Buckminsterfullerene. Nature 318, 162. https://doi.org/10.1038/318162a0 (1985).
4. David, W. I. F. et al. Crystal structure and bonding of ordered C60. Nature 353, 147. https://doi.org/10.1038/353147a0 (1991).
5. Fowler, P. W. & Manolopoulos, D. E. An Atlas of Fullerenes (Courier Corporation, 2007).