Intensity analysis of overlapped discrete and continuous absorption by spectral simulation: The electronic transition moment for the B–X system in I2

Abstract

The spectrum of I(2) is examined anew in the wavelength region 520-640 nm, where discrete absorption in the B-X transition is prominent. The spectrum is recorded with high quantitative precision at moderate resolution (0.1 nm) and is analyzed by least-squares spectral simulation, yielding the B-X electronic transition strength ∣μ(e)∣(2) with unprecedented precision (<2% relative standard error) over most of the studied region. The analysis also yields directly new estimates of the continuous absorption in this region, which support previous assessments of the A ← X transition but lower the C((1)Π(u)) ← X transition strength by 25%. The new analysis method is applicable to any situation where the discrete spectrum can be simulated reliably.

Finite-Field Calculations of Transition Properties by the Fock Space Relativistic Coupled Cluster Method: Transitions between Different Fock Space Sectors

“…u transition is of particular interest for testing relativistic transition dipole calculation techniques since it corresponds to the forbidden singlet-triplet ( 1 Σ + g − 3 Π u ) excitation at the non-relativistic (or scalar relativistic) limit. The empirical dependence of the X0 + g − B0 + u transition dipole moment on the internuclear separation derived from a large amount of experimental data by Tellinghuisen [55] is expected to be accurate within a few percents at least in the vicinity of the ground-state equilibrium point. Our calculations were performed using the [9s 10p 8d 5 f 3g] basis set for iodine constructed in the same way as for Xe, except for the absence of Rydberg-like functions which are not needed to describe the valence-like states under study.…”

“…X0 + g − B0 +u transition dipole moment function of the I 2 molecule. Bold red line: empirical function from Ref [55],. solid and dashed blue lines: finite-field (D FF X−B ) and model-state (D MS X−B ) FS RCC estimates respectively, green dot-dashed line: quasirelativistic multireference perturbation theory data[56].…”

Finite-Field Calculations of Transition Properties by the Fock Space Relativistic Coupled Cluster Method: Transitions between Different Fock Space Sectors

“…The rather intensive X0 + g −B0 + u transition is of particular interest for testing relativistic transition dipole calculation techniques since it corresponds to the forbidden singlet-triplet ( 1 Σ + g − 3 Π u ) excitation at the non-relativistic (or scalar relativistic) limit. The empirical dependence of the X0 + g − B0 + u transition dipole moment on the internuclear separation derived from a large amount of experimental data by Tellinghuisen [55] is expected to be accurate within a few percent at least in the vicinity of the ground-state equilibrium point. Our calculations were performed using the [9s 10p 8d 5 f 3g] basis set for iodine constructed in the same way as for Xe, except for the absence of Rydberg-like functions which are not needed to describe the valence-like states under study.…”

“…X0 + g − B0 +u transition dipole moment function of the I 2 molecule: bold red line, empirical function from Tellinghuisen[55]; solid and dashed blue lines: finite-field (D FF X−B ) and model-state (D MS X−B ) FS RCC estimates, respectively; green dot-dashed line, quasirelativistic multireference perturbation theory data[56]; dotted violet line, the dependence of the largest amplitude in T ) on the internuclear separation.…”

Quantum dynamics and spectroscopy of dihalogens in solid matrices. II. Theoretical aspects and G-MCTDH simulations of time-resolved coherent Raman spectra of Schrödinger cat states of the embedded I2Kr18 cluster

“…Moreover, Feynman pathways which involve E ←→ B transitions are favored by the fact that the TDM µ EB is roughly twice as large as µ BX . 30,31 Under the just stated experimental conditions, the Stokes signal as a function of pump-probe delay P…”