Dichromium and trichromium

Abstract

Resonance and preresonance Raman spectra are obtained from chromium-containing argon matrics. Two progressions are assigned to Cr2 and Cr3, the former with optical constants ω″e=427.5 and ω″ex″e=15.75 cm−1 and the latter with ω″e=313 and ω″ex″e=2 cm−1. When not in resonance two other lines at 123 and 226 cm−1 were observed and ascribed to the bending and asymmetric stretching vibration of Cr3, while the vibration forming the progression was taken to be the symmetric stretch. From this, Cr3 is deduced to be a molecule with C2v symmetry but with an apical angle near 60°, suggesting that it is perhaps a Jahn–Teller distorted D3h molecule.

Vibrations of small cobalt clusters on low-index surfaces of copper: Tight-binding simulations

“…In equilibrium, the free Co dimer vibrates with a frequency of 36.48 meV. This result is in excellent agreement with photoelectron spectroscopy data 34.74Ϯ 2.50 meV and 36 meV obtained by Leopold and Lineberger 66 and by DiLella et al, 67 respectively. Ab initio calculations of Co 2 vibrations 51 give values in the range 52-55 meV which are 50% higher than our computation frequency while a lower vibrational energy of 29.3 meV is obtained from the TBHH evaluation.…”

Electronic and magnetic properties ofConMomnanoclusters from density functional calculations (n+m=xand 2Liebing1, Martín2, Trepte3 et al. 2015Phys. Rev. B

“…[21] and references therein) and reasonably close to the experimental value of ω =477 cm −1 , see Ref. [55,58]. The ionization potential of 6.7 eV is in good agreement with experimental studies (6.4 eV ≤ IP ≤ 8.0 eV; see Ref.…”

Cobalt clusters (Con, n⩽6) and their anions

“…Hales et al [32] measured the ionization potential (IP) of the dimer as 6.42 eV which was estimated as 6.26 ± 0.16 eV previously [35]. Vibrational frequency of Co 2 has been determined by different groups as the following: 290 cm À1 [36], 280 ± 20 cm À1 [37], 296.8 ± 5.4 cm À1 [38]. We report the results for the properties of Co 2 from previous theoretical calculations in Table 1 together with the experimental estimations.…”