Ab initio calculation of temperature effects in the optical response of open-shell sodium clusters

del Puerto, Marie Lopez; Tiago, Murilo L.; Chelikowsky, James R.
October 2007
Journal of Chemical Physics;10/14/2007, Vol. 127 Issue 14, p144311
Academic Journal
Many properties of atomic clusters have been found to be size dependent, e.g., the optical response. There are, however, factors other than size that can also play an important role in determining the properties of nanoscale systems. Temperature, in particular, has been shown to have a strong effect on the optical response of open-shell sodium clusters. We incorporate the temperature effect on the optical absorption spectra by combining pseudopotentials, Langevin molecular dynamics, and time-dependent density functional theory. We have done calculations for several open-shell sodium clusters, Na4+, Na7+, and Na11+, for which experimental data are available for comparison. We find that the positions of the lower energy peaks of the calculated spectra correspond very well to the peaks in the experimental spectra, although the local density approximation tends to overestimate the gap of the smaller clusters by up to 0.2 eV and underestimate the gap of the largest cluster by 0.4 eV. We fit the width of the peaks in the lower-temperature calculations to the corresponding experimental result to obtain the instrumental linewidth. We then use this same width for the high-temperature calculations and find very good agreement with experiment. Finally, we analyze the transitions that contribute to the observed peaks in the absorption spectra and we plot the effective valence charge density for specific transitions for each cluster. We find that for the two smaller clusters the absorption spectra are dominated by transitions from the occupied levels to a few (three for Na4+ and five for Na7+) empty levels, although the contribution from transitions to other empty levels can still be significant. In contrast, the absorption spectra for Na11+ come from a greater mixture of transitions as evidenced in the analysis as well as in the plot of the effective valence charge density.


Related Articles

  • Infrared-active vibron bands associated with substitutional impurities in solid parahydrogen. Hinde, Robert J. // Journal of Chemical Physics;7/1/2003, Vol. 119 Issue 1, p6 

    We present a model for the line shapes of infrared-active Q[SUB1](0) vibron bands observed in solid parahydrogen doped with low concentrations of spherical substitutional impurities. The line shapes are highly sensitive to the H[SUB2] vibrational dependence of the dopant-H[SUB2] interaction....

  • Effect of chlorine impurities on the long-wavelength absorption edge of CdTe single crystals. Popovych, V. D.; Potera, P.; Virt, I. S.; Bilyk, M. F. // Semiconductors;Jun2009, Vol. 43 Issue 6, p730 

    The optical absorption spectra of the nominally undoped and Cl-doped CdTe single crystals in the region of the fundamental long-wavelength absorption edge are studied at room temperature. The crystals are grown by the modified physical vapor transport method. It is shown that the exponential...

  • Nature of p-Electronic Transitions in UV Spectra of Deoxyvasicinone and Its Derivatives. Kristallovich, E. L.; Eshimbetov, A. G.; Chuvylkin, N. D.; Belen kii, L. I.; Shakhidoyatov, Kh. M. // Chemistry of Natural Compounds;Sep/Oct2003, Vol. 39 Issue 5, p495 

    The principal types of electronic transitions in absorption spectra of deoxyvasicinone and its 6-amino- and 6-nitro-derivatives were determined by analyzing the electron-density distributions in excited states calculated using ZINDO/S.

  • The role of relativity in the optical response of gold within the time-dependent current-density-functional theory. Romaniello, P.; de Boeij, P. L. // Journal of Chemical Physics;4/22/2005, Vol. 122 Issue 16, p164303 

    We included relativistic effects in the formulation of the time-dependent current-density-functional theory for the calculation of linear response properties of metals [P. Romaniello and P. L. de Boeij, Phys. Rev. B (to be published)]. We treat the dominant scalar-relativistic effects using the...

  • Structure and electronic absorption spectra of nematogenic alkoxycinnamic acids - a comparative study based on semiempirical and DFT methods. Praveen, Pogula; Ojha, Durga // Journal of Molecular Modeling;Apr2012, Vol. 18 Issue 4, p1513 

    Structure of nematogenic p- n-Alkoxy cinnamic acids ( nOCAC) with various alkyl chain carbon atoms ( n = 2, 4, 6, 8) has been optimized using density functional B3LYP with 6-31+G (d) basis set using crystallographic geometry as input. Using the optimized geometry, electronic structure of the...

  • Laser diode array (LDA) end-pumped multi-watt Yb:YAG 1030 nm laser. HONGZHONG CAO; HONGYAN PENG; MEIHENG ZHANG; YUQIANG CHEN; BING ZHANG; BAOLING CHEN; JUN ZHANG; TONGHUA WU; XIANGMIN ZHAO; HUIMINGTAN // Optica Applicata;2010, Vol. 40 Issue 3, p653 

    A LDA (laser diode array) end-pumped Yb:YAG 1030 nm laser is reported. Using a plano-concave resonator, with input pump power of 11.79 W, 2.55 W TEM00 continuous wave laser at 1030 nm was obtained. The effective focal length of the thermal lens is also calculated.

  • Spectral specific features of the interaction of two fields of arbitrary intensity with three-level Λ-systems. Parkhomenko, A. I.; Shalagin, A. M. // Optics & Spectroscopy;Dec2007, Vol. 103 Issue 6, p976 

    The spectrum of absorption of a probe field of arbitrary intensity by three-level atoms with the Λ configuration of levels in the field of a strong electromagnetic wave acting on an adjacent transition is studied theoretically. It is shown that the supernarrow resonance, revealed earlier by...

  • Study of absorption spectra of Er3+ in KTaO3 crystals. Skvortsov, A. P.; Trepakov, V. A.; Kapphan, S.; Dejneka, A.; Jastrabik, L. // Physics of the Solid State;Jul2009, Vol. 51 Issue 7, p1470 

    The first results of the study of optical absorption spectra of KTaO3: Er3+ crystals are presented. In the 350–660-nm region, lines are observed deriving from intraconfigurational electronic transitions from the 4 I15/2 ground state to levels of the 4 F9/2, 4 S3/2, 2 H11/2, 4 F7/2, 4...

  • Analysis of the two-photon absorption spectrum of benzonitrile based on the direct quantum-mechanical calculation of the intensity distribution. Burova, T.; Anashkin, A. // Optics & Spectroscopy;Nov2007, Vol. 103 Issue 5, p728 

    A direct quantum-mechanical calculation of the intensity distribution in the two-photon absorption spectrum of benzonitrile is performed taking into account the Herzberg-Teller effect. The excitation mechanism of all the observed lines, including lines corresponding to the excitation of...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics