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IrGa is Tetraauricupride structured and crystallizes in the cubic Pm-3m space group. The structure is three-dimensional. Ir is bonded in a body-centered cubic geometry to eight equivalent Ga atoms. All Ir–Ga bond lengths are 2.65 Å. Ga is bonded in a body-centered cubic geometry to eight equivalent Ir atoms.
Sr3(IrGa)4 crystallizes in the cubic I-43m space group. The structure is three-dimensional. Sr is bonded in a 12-coordinate geometry to four equivalent Ir and four equivalent Ga atoms. All Sr–Ir bond lengths are 3.24 Å. All Sr–Ga bond lengths are 3.21 Å. Ir is bonded in a 4-coordinate geometry to three equivalent Sr, three equivalent Ir, and four equivalent Ga atoms. All Ir–Ir bond lengths are 2.81 Å. There are one shorter (2.45 Å) and three longer (2.60 Å) Ir–Ga bond lengths. Ga is bonded in a 7-coordinate geometry to three equivalent Sr and four equivalent Ir atoms.
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We investigate the time-resolved dynamics of interatomic Coulombic decay in NeKr dimers after neon inner-valence photoionization using a synchrotron light source.
We have conducted an experimental study on the photo double ionization (PDI) of carbon dioxide dimers and oxygen dimers, while focusing on the dissociation dynamics upon single photon absorption. The results in terms of the kinetic energy and angular distributions of the charged particles show unambiguous experimental evidence of intermolecular Coulombic decay (ICD) in carbon dioxide dimers. In the oxygen dimer, the results show that ICD is accompanied by knock-off ionization mechanisms.
Employing a coincidence three-dimensional momentum imaging technique, we investigate the ultrafast, intense laser-induced dissociation of a metastable NO 2+ ion beam into N + + O + . Based on the kinetic energy release and angular distributions, measured using both 774-nm and second-order-harmonic 387-nm pulses, we show that the main processes driving dissociation in pulses of about 10 14 W/cm 2 peak intensity are one- and two-photon transitions from the X 2 Σ + ground state to the A 2 Π first-excited state. First-order perturbation theory calculations also corroborate these findings.
We study laser-induced dissociation of a metastable NO 2+ ion-beam target into N + +O + , focusing on the prominent contribution by molecules breaking parallel to the polarization at high peak laser intensity (~10 15 W/cm 2 ). Our experimental results and time-dependent Schrödinger equation calculations show that, contrary to commonly held intuition that electronic transitions always prevail, the dominant process underlying this highly aligned dissociation is a multiphoton permanent-dipole transition involving only the electronic ground state and leading to its vibrational continuum. Strong-field permanent-dipole transitions should thus be considered generally, as they may play a significant role in other heteronuclear molecules. Moreover, their role should only grow in importance for longer wavelengths, a trending direction in ultrafast laser studies.
Vibrational Cooper minima due to weak dipole coupling were previously observed in strong-field dissociation of H 2 + as minima in the kinetic-energy-release (KER) spectrum [McKenna et al., Phys. Rev. Lett. 103, 103006 (2009)]. We demonstrate in two independent experiments that these vibrational Cooper minima occur more generally and can be used as “fingerprints” to identify the final electronic state in the dissociation pathway. In the first experiment, we show the wavelength dependence of the vibrational Cooper minima observed in the KER spectrum of O 2 + dissociation induced by 396- and 264-nm photons. These minima appear at the locations predicted by our first-order perturbation-theory calculations. In the second experiment, a delay-dependent KER spectrum is obtained from O 2 using an ionizing pump and a dissociating probe, then Fourier-transformed to generate a spin-rotation quantum beat spectrum of O 2 + . As a result, this spectrum shows vibrational Cooper minima at the expected locations, confirming their presence in another observable. In this case, these minima are used to identify the dissociation pathway.