scholarly journals MCSCF-CI Calculations of Radiative Transition Probabilities of PH and PD

1986 ◽  
Vol 41 (5) ◽  
pp. 719-723 ◽  
Author(s):  
J. Senekowitsch ◽  
P. Rosmus ◽  
H. J. Wemer ◽  
M. Larsson

Potential energy, dipole moment, and electronic transition moment functions for the A 3Πand X3Σ- states of PH have been calculated from highly correlated electronic wavefunctions. The electric dipole moments in the vibrational ground state of PH are calculated to be 0.637 Debye (A 3Π) and 0.403 Debye (X3Σ-). The predicted rates of spontaneous emission between low lying vibrational states of the X state lie in the range of 46 to 109 sec-1 (PH) and 12 to 30 sec-1 (PD). The calculated radiative lifetime of the v' = 0 level in the A 3Π state of 400 ns is lower by about 10 percent than the most recent experimental value. The classical intersection of the 5Σ- and the A 3Πstate has been calculated to lie between v' = 2 and 3 with an expected uncertainty of about 500 cm−1, whereas the onset of the rotationally dependent predissociation lies at v' = 0, J' = 11.

1979 ◽  
Vol 57 (8) ◽  
pp. 1178-1184 ◽  
Author(s):  
M. L. Sink ◽  
A. D. Bandrauk

Ab initio Cl calculations of the transition moment for the B′2Σ+–X2Σ+ transition in MgH are reported. Theoretical values for the Franck–Condon factors, band strengths, band oscillator strengths, and transition probabilities have been computed for MgH and MgD. An analysis of our results for this system predicts many bands to be observable which have not yet been identified. Dipole moment functions and vibrationally averaged dipole moments are given for the X2Σ+, A2Π, and B′2Σ+ electronic states.


2020 ◽  
Vol 98 (12) ◽  
pp. 806-813
Author(s):  
Gabriel Fernando de Melo ◽  
Fernando R. Ornellas

A manifold of singlet, triplet, and quintet electronic states of the sulfur monoiodide cation (SI+) correlating with the two lowest-lying dissociation channels is characterized theoretically at a high level of theoretical treatment (SA-CASSCF/MRCI+Q/aug-cc-pV5Z) for the first time. Potential energy curves, also including the effect of spin-orbit couplings, are constructed and the associated spectroscopic parameters and dissociation energies determined. As to the molecular polarity, we computed the dipole moment as a function of the internuclear distance and the associated vibrationally averaged dipole moments. Transition dipole moment functions were also constructed, and transition probabilities, as expressed by the Einstein coefficients for spontaneous emission, were evaluated for selected pairs of states that we identify as more easily accessible to experimental investigation. An analysis of the bonding in this system is also presented. Together with previous studies on neutral and cationic sulfur-monohalides, one has a comprehensive view of this series of molecules.


1973 ◽  
Vol 28 (5) ◽  
pp. 717-724 ◽  
Author(s):  
F. J. Comes ◽  
E. H. Fink

Excitation of CO molecules into the lowest vibrational level of the B1Σ+ electronic state by absorption of the (B 1Σ+υ′=0 →X 1Σ+ ,υ′′=0) resonance band at 1150 Å has been studied under various experimental conditions by observing the steady state fluorescence of the (B 1Σ+→A1Π) Angstrom bands. Stern-Volmer plots of the fluorescence intensities at the addition of various foreign gases yielded straight lines whose slopes k̃qм = kqм · τeff were strongly dependent on the CO sample pressure. This effect was found to be due to changes of the effective radiative lifetime of the B 1Σ+υ′=0 because of resonance trapping of the (0,0) band of the (B → X) fluorescence. The CO(B 1Σ+υ′=0) molecules are found to be quenched by He, Ne, Ar, H2 and D2 with effective collision cross sections of 0.23, 0.48, 22.4, 10.7, and 11.4 Å2, respectively, at 298 °K. In addition, an approximate value for the ratio ABA/ (ABA+ABX)of the radiative transition probabilities of the (B → A) and (B → X) transitions could be derived from the measurements.


1984 ◽  
Vol 39 (4) ◽  
pp. 349-353 ◽  
Author(s):  
Robert Klein ◽  
Pavel Rosmus

Near equilibrium potential energy and dipole moment functions have been calculated for the electronic ground state of the XeH+ ion from highly correlated SCEP/CEPA electronic wavefunctions. The following spectroscopic constants for 132XeH+ are obtained:Re= 1.611 ± 0.005 Å, ωe = 2313 ± 50cm-1, ωexe = 41 ± 5cm-1 and D0(Xe+ + H) = 3.90 ± 0.1 eV.Infrared transition dipole matrix elements and probability coefficients for 132XeH+ and 132XeD+ are given. The electric dipole moment functions of the protonated rare gas atoms HeH+ to XeH+ are discussed.


2008 ◽  
Vol 73 (6-7) ◽  
pp. 873-897 ◽  
Author(s):  
Vladimír Špirko ◽  
Ota Bludský ◽  
Wolfgang P. Kraemer

The adiabatic three-dimensional potential energy surface and the corresponding dipole moment surface describing the ground electronic state of HN2+ (Χ1Σ+) are calculated at different levels of ab initio theory. The calculations cover the entire bound part of the potential up to its lowest dissociation channel including the isomerization barrier. Energies of all bound vibrational and low-lying ro-vibrational levels are determined in a fully variational procedure using the Suttcliffe-Tennyson Hamiltonian for triatomic molecules. They are in close agreement with the available experimental numbers. From the dipole moment function effective dipoles and transition moments are obtained for all the calculated vibrational and ro-vibrational states. Statistical tools such as the density of states or the nearest-neighbor level spacing distribution (NNSD) are applied to describe and analyse general patterns and characteristics of the energy and dipole results calculated for the massively large number of states of the strongly bound HN2+ ion and its deuterated isotopomer.


Sign in / Sign up

Export Citation Format

Share Document