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Title: Enhanced Energetic Stability and Optical Activity of Symmetry-Reduced C60

Abstract

Since its discovery in 1985, the celebrated geodesic cage structure of the C{sub 60} molecule has been recognized: a truncated icosahedron in which all sixty vertices are equivalent and has the full I{sub h} symmetry, making it thus far the most spherical of all known molecules. Inherent in this high symmetry is an intricate network of electron-phonon coupling, evident in phonon progressions and vibronic peak broadening, and resulting in structural distortions of neutral C{sub 60} in the presence of solvent. Within the I{sub h} symmetry group of this molecule, of the forty-six distinct vibrational frequencies only ten are Raman-active and four are IR-active (in the first order), while the remaining 32 modes are optically silent. Symmetry-reduced structures of C{sub 60} would activate some of these silent modes, which could then be amenable to experimental verification such as in resonance Raman scattering. Here, quantum chemical calculations within density functional theory establish for the first times (1) lower-symmetry, energetically more stable structures for C{sub 60}, the lowest of which is of D{sub 3d} symmetry, and with a new assignment of the ground state as the {sup 1}A{sub 1g} state, (2) the activation of some IR and Raman I{sub h} silent modes: themore » IR H{sub u} mode around 540 cm{sup -1} and G{sub u} band at 1465 cm{sup -1}, and the Raman G{sub g} mode around 1530 cm{sup -1}.« less

Authors:
Publication Date:
Research Org.:
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
894005
Report Number(s):
UCRL-JRNL-218407
TRN: US0700023
DOE Contract Number:
W-7405-ENG-48
Resource Type:
Journal Article
Resource Relation:
Journal Name: Chemical Physics Letters, vol. 424, no. 1-3, June 12, 2006, pp. 139-141
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; ELECTRON-PHONON COUPLING; FUNCTIONALS; GEODESICS; GROUND STATES; OPTICAL ACTIVITY; PHONONS; RESONANCE; SCATTERING; STABILITY; SYMMETRY; SYMMETRY GROUPS; VERIFICATION

Citation Formats

Manaa, M R. Enhanced Energetic Stability and Optical Activity of Symmetry-Reduced C60. United States: N. p., 2006. Web. doi:10.1016/j.cplett.2006.04.059.
Manaa, M R. Enhanced Energetic Stability and Optical Activity of Symmetry-Reduced C60. United States. doi:10.1016/j.cplett.2006.04.059.
Manaa, M R. Tue . "Enhanced Energetic Stability and Optical Activity of Symmetry-Reduced C60". United States. doi:10.1016/j.cplett.2006.04.059. https://www.osti.gov/servlets/purl/894005.
@article{osti_894005,
title = {Enhanced Energetic Stability and Optical Activity of Symmetry-Reduced C60},
author = {Manaa, M R},
abstractNote = {Since its discovery in 1985, the celebrated geodesic cage structure of the C{sub 60} molecule has been recognized: a truncated icosahedron in which all sixty vertices are equivalent and has the full I{sub h} symmetry, making it thus far the most spherical of all known molecules. Inherent in this high symmetry is an intricate network of electron-phonon coupling, evident in phonon progressions and vibronic peak broadening, and resulting in structural distortions of neutral C{sub 60} in the presence of solvent. Within the I{sub h} symmetry group of this molecule, of the forty-six distinct vibrational frequencies only ten are Raman-active and four are IR-active (in the first order), while the remaining 32 modes are optically silent. Symmetry-reduced structures of C{sub 60} would activate some of these silent modes, which could then be amenable to experimental verification such as in resonance Raman scattering. Here, quantum chemical calculations within density functional theory establish for the first times (1) lower-symmetry, energetically more stable structures for C{sub 60}, the lowest of which is of D{sub 3d} symmetry, and with a new assignment of the ground state as the {sup 1}A{sub 1g} state, (2) the activation of some IR and Raman I{sub h} silent modes: the IR H{sub u} mode around 540 cm{sup -1} and G{sub u} band at 1465 cm{sup -1}, and the Raman G{sub g} mode around 1530 cm{sup -1}.},
doi = {10.1016/j.cplett.2006.04.059},
journal = {Chemical Physics Letters, vol. 424, no. 1-3, June 12, 2006, pp. 139-141},
number = ,
volume = ,
place = {United States},
year = {Tue Jan 24 00:00:00 EST 2006},
month = {Tue Jan 24 00:00:00 EST 2006}
}
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