Pump-and-probe studies of the E1(6 (3)S1)A0(+)(5 (3)P1) excitation spectrum of CdAr in a supersonic beam

The lowest-lying Rydberg state of CdAr van der Waals complex: The improved characterization of the interatomic potential

Previous characterization of the double-well E³Σ₁⁺6³S₁ - Rydberg state outer potential well E³Σ_1out⁺ in CdAr van der Waals (vdW) complex has been based on detection of the E³Σ₁⁺←B³Σ₁⁺5³P₁ (υ″=0-2) transitions only. In this study, the gap in the limited characterization of the E³Σ₁⁺_out shallow well and the neighbouring potential barrier has been filled by recording bound (υ') ← bound (υ″=1-4) and free ← bound (υ″=0-4) excitation spectra. The result, spectroscopic description of the E³Σ_1out⁺ well along with the potential barrier have been concluded from simulations of the recorded spectra. The results were compared with those published previously.

The E3Σ1+ (63S1)←A3Π0+(53P1) transition in CdAr revisited: The spectrum and new analysis of the E3Σ1+ Rydberg state interatomic potential

Revisited study of the E³Σ₁⁺ (6³S₁)←A³Π₀₊(5³P₁) transition in CdAr using both theoretical and experimental approach is presented. Systematic detection of the E³Σ₁⁺_in,υ'←A³Π₀₊,υ″=6 transition frequencies with higher accuracy and spectrally narrower laser extended and improved analysis and simulation of the LIF excitation spectrum. More consistent characterization of the E³Σ₁⁺_in-Rydberg state inner well using inversed perturbation approach methodology was achieved. Free←bound transitions in the E³Σ₁⁺_in←A³Π₀₊,υ″=6 excitation were taken into account in the analysis and simulation of the recorded spectrum. The updated spectroscopic characterization of the A³Π₀₊ state was also revisited.

Interaction potentials and spectroscopy of Hg+.Rg and Cd+.Rg and transport coefficients for Hg+ and Cd+ in Rg (Rg=He-Rn)

High-level ab initio calculations have been performed on the Hg(+).Rg and Cd(+).Rg species, where Rg-He-Rn. Potential-energy curves have been calculated over a wide range of internuclear separation, sampling the repulsive, equilibrium, and long-range regions. From these curves, rovibrational and spectroscopic constants were derived and compared to those available from previous studies. In addition, transport coefficients were calculated and compared to the available experimental data for the cases of Hg(+) in He, Ne, and Ar. There are two interesting features relating to the mobility results. One is the development of a "mobility minimum" for Hg(+) in the heavier rare gases--with weaker minima being found for Cd(+); a "rule of thumb" is presented for determining when mobility minima might appear. The second is that excellent agreement is found for the direct calculation of mobilities for Hg(+) in (22)Ne, and those obtained by scaling the (20)Ne mobilities. The latter result allows us to conclude that the mobilities of the various combinations of isotopes can be calculated from the results herein via a mass scaling.

The structure of the lowest electronic Rydberg state of CdAr complex determined by laser double resonance method in a supersonic jet-expansion beam

The lowest E1(3Sigma(+)) Rydberg state of the CdAr van der Waals (vdW) complex was investigated by means of an optical-optical double resonance (OODR) method of laser spectroscopy in conjunction with a free jet-expansion molecular beam. Two dye lasers were employed for the two-step excitation. The A0(+)(3Pi(+)) and B1(3Sigma(+)) states were used as intermediates in the excitation process from the X0(+)(1Sigma(+)) ground state. Two types of bound-bound excitation spectra of the E1<--A0(+) and E1<--B1 transitions were recorded indicating the existence of two, well defined minima in the E1-state potential energy (PE) curve. First, considerably deep, with the well depth of D(e)'(E1(2))=1309.0 cm(-1) and second, separated by a positive PE barrier, with D(e)'(E1(2))=24.2 cm(-1). Combination of bound-bound and first-time observed bound-free excitation spectra enabled a complete determination of the spectroscopical parameters of the PE curve of the E1-Rydberg state, the height of the PE barrier and its approximate location. In the excitation spectra of the E1<--B1 transition, a nodal structure of the bound-free transitions was observed and elucidated by a projection of the B1-state vibrational wave-functions onto the E1-state potential barrier and/or onto the repulsive part of the E1-state PE curve. The experimental results of our investigation coincides well with recently published results of ab initio calculation of Czuchaj and co-workers [Chem. Phys. 248 (1999) 1; Chem Phys. 263 (2001) 7; Theor. Chem Acc. 105 (2001) 219].

Interatomic potentials of cadmium-argon B1(3sigma+) and X0+(1sigma+) states based on near-dissociation expansion and 'hot' bands observed in the B1 <-- X0+ excitation spectrum

B1(3sigma+) <-- X0+(1sigma+) excitation spectrum of the cadmium-argon van der Waals molecule has been recorded in the experiment of a continuous supersonic molecular beam crossed with a pulsed dye laser beam. The B1-state dissociation energy was directly observed and a long-range behavior of the B1-state intermolecular potential was derived using a near-dissociation expansion procedure of LeRoy and Bernstein. A first-time direct determination of the X0+ ground state characteristics based on 'hot' bands observed is presented as well. The new result is compared with other experimental and theoretical reports available in the literature.