Ab initio study of spectroscopic properties of the calcium hydride molecular ion

Habli, Héla; Ghalla, Houcine; Oujia, Brahim; Gadéa, Florent Xavier

doi:10.1140/epjd/e2011-10689-y

Cited by 39 publications

(58 citation statements)

References 42 publications

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“…These results are consistent with previous analysis of LiH excited states and with the finding that the ionic-3 s and 3 p state crossings with the ionic state occur at about 10 and 18 Å. 22,71,72,90 Figure 4 shows that the nonorthogonal VB states can indeed be orthogonalized to yield diabatic states qualitatively similar to those from the Three-Fold-Way ATD transformation procedure, although the 2 p diabatic state is much more repulsive and shows no particular dependence to the higher adiabatic curves. An overlap-dependent mixing of certain VB states before the diagonalization process is needed to represent orbital hybridization.…”

Section: Resultssupporting

confidence: 93%

Diabatic-At-Construction Method for Diabatic and Adiabatic Ground and Excited States Based on Multistate Density Functional Theory

Grofe

Truhlar

et al. 2017

J. Chem. Theory Comput.

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We describe a diabatic-at-construction (DAC) strategy for defining diabatic states to determine the adiabatic ground and excited electronic states and their potential energy surfaces using the multistate density functional theory (MSDFT). The DAC approach differs in two fundamental ways from the adiabatic-to-diabatic (ATD) procedures that transform a set of preselected adiabatic electronic states to a new representation. (1) The DAC states are defined in the first computation step to form an active space, whose configuration interaction produces the adiabatic ground and excited states in the second step of MSDFT. Thus, they do not result from a similarity transformation of the adiabatic states as in the ATD procedure; they are the basis for producing the adiabatic states. The appropriateness and completeness of the DAC active space can be validated by comparison with experimental observables of the ground and excited states. (2) The DAC diabatic states are defined using the valence bond characters of the asymptotic dissociation limits of the adiabatic states of interest, and they are strictly maintained at all molecular geometries. Consequently, DAC diabatic states have specific and well-defined physical and chemical meanings that can be used for understanding the nature of the adiabatic states and their energetic components. Here we present results for the four lowest singlet states of LiH and compare them to a well-tested ATD diabatization method, namely the 3-fold way; the comparison reveals both similarities and differences between the ATD diabatic states and the orthogonalized DAC diabatic states. Furthermore, MSDFT can provide a quantitative description of the ground and excited states for LiH with multiple strongly and weakly avoided curve crossings spanning over 10 Å of interatomic separation.

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Section: Resultssupporting

confidence: 93%

Diabatic-At-Construction Method for Diabatic and Adiabatic Ground and Excited States Based on Multistate Density Functional Theory

Grofe

Truhlar

et al. 2017

J. Chem. Theory Comput.

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“…[22]. We assigned peaks based on theoretical predictions in the literature using a complete-active-space approach (CASPT2) [30] and a core pseudopotentialconfiguration interaction approach (CCP-CI) [31]. The CASPT2 transition frequencies are blue-shifted and the CCP-PI transition frequencies are red-shifted relative to the data, Table 1.…”

Section: Resultsmentioning

confidence: 99%

Vibronic Spectroscopy of Sympathetically Cooled CaH⁺

et al. 2016

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We report the measurement of the 1 1 Σ −→ 2 1 Σ transition of CaH + by resonance-enhanced photodissociation of CaH + that is co-trapped with laser-cooled Ca + . We observe four resonances that we assign to transitions from the vibrational v=0 ground state to the v =1-4 excited states based on theoretical predictions. A simple theoretical model that assumes instantaneous dissociation after resonant excitation yield results in good agreement with the observed spectral features except for the unobserved v =0 peak. The resolution of our experiment is limited by the mode-locked excitation laser, but this survey spectroscopy enables future rotationally resolved studies with applications in astrochemistry and precision measurement. 1

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“…Interestingly, the 1 Σ + states present an important series of avoided crossing. Their highly potential energy is strongly imprinted by the ionic state Sr 2+ H − like for BaH + , CaH + and MgH + systems . The multiplicity of crossings leads to unusual potential shapes with various wells which may trap vibrational levels in various R ranges.…”

Section: Resultsmentioning

confidence: 99%

“…As pointed out in the work of Habli et al, the l ‐dependent CPP approach with several cutoff radii leads to an incorrect asymptotic behavior possibly caused by an underestimation of nuclear and electronic fields associated to the truncation in the l ‐expansion. We, therefore, used here the CPP l ‐independent form and a single cutoff radius ( ρ Sr ) in the spherical function F ( R ):

F = true[1 - \exp (- \frac{R_{c j}^{2}}{ρ_{c}^{2}}) true]

…”

Section: Theory and Computational Detailsmentioning

confidence: 99%

See 1 more Smart Citation

Ab initio calculation of the electronic structure of the strontium hydride ion (SrH⁺)

Habli

Mejrissi

Issaoui

et al. 2014

Int J of Quantum Chemistry

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The potentials, spectroscopic properties and electric dipole moments of SrH+ are computed for 63 molecular states dissociating up to Sr2+ + H− using an ab initio approach. The ab initio formalism is based on large basis sets, nonempirical atomic pseudopotential for strontium core, correlation treatment for core valence through the effective core polarization potentials and for valence through full valence configuration interaction. Our theoretical molecular constants match published values very well and a large amount of new results is produced. Unusual potential shapes are found in 1Σ+ states often caused by avoided crossing series between them and imprinted by the ionic state Sr2+H−. The high potential energy curves suggest, it is possible to form H− or at least to neutralize H+ in collisions with strontium. © 2014 Wiley Periodicals, Inc.

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Ab initio study of spectroscopic properties of the calcium hydride molecular ion

Cited by 39 publications

References 42 publications

Diabatic-At-Construction Method for Diabatic and Adiabatic Ground and Excited States Based on Multistate Density Functional Theory

Diabatic-At-Construction Method for Diabatic and Adiabatic Ground and Excited States Based on Multistate Density Functional Theory

Vibronic Spectroscopy of Sympathetically Cooled CaH⁺

Ab initio calculation of the electronic structure of the strontium hydride ion (SrH⁺)

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Ab initio study of spectroscopic properties of the calcium hydride molecular ion

Cited by 39 publications

References 42 publications

Diabatic-At-Construction Method for Diabatic and Adiabatic Ground and Excited States Based on Multistate Density Functional Theory

Diabatic-At-Construction Method for Diabatic and Adiabatic Ground and Excited States Based on Multistate Density Functional Theory

Vibronic Spectroscopy of Sympathetically Cooled CaH+

Ab initio calculation of the electronic structure of the strontium hydride ion (SrH+)

Contact Info

Product

Resources

About

Vibronic Spectroscopy of Sympathetically Cooled CaH⁺

Ab initio calculation of the electronic structure of the strontium hydride ion (SrH⁺)