Calculation of adiabatic potentials of Li2

Using the Multi-Reference Configuration Interaction method, the adiabatic potential energy surfaces of Li3 are computed. The two lowest electronic states are bound and exhibit a conical intersection. By fitting the calculated potential energy surfaces to the cubic E ⊗ ε Jahn-Teller model we extract the effective Jahn-Teller parameters corresponding to Li3. These are used to set up the transformation matrix which transforms from the adiabatic to a diabatic representation. This diabatization method gives a Hamiltonian for Li3 which is free from singular adiabatic couplings and should be accurate for large internuclear distances, and it thereby allows for bound dynamics in the vicinity of the conical intersection to be explored.

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“…We also achieve very good agreement with the potential energy curves reported by Hotta et al [32]. show the results of Jasik et al [31].…”

Section: A Potential Energy Curves Of Li2supporting

confidence: 81%

“…2. We compare our potential energy curves with those calculated by Jasik et al using a CI technique [31], where only the valence electrons are treated explicitly. As can be seen an excellent agreement is obtained.…”

Section: A Potential Energy Curves Of Li2mentioning

confidence: 99%

A diabatic representation of the two lowest electronic states of Li3

Ghassemi

Larson

2014

The Journal of Chemical Physics

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“…This is also necessary for valence electron full configuration interaction (FCI) calculations where an ECP (a physically equivalent representation to the frozen core approximation which has no CV correlation) is substituted for the atomic electrons. This method has been used with great success for calculating both lithium dimer potential curves [25] and trimer potential surfaces of potassium [12].…”

Section: Core-valence Correlationmentioning

confidence: 99%

Potential energy surface of the 1²A′ Li₂ + Li doublet ground state

Byrd

Michels

Côté

2009

Int J of Quantum Chemistry

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The lowest doublet electronic state for the lithium trimer (1 2 A ) is calculated for use in three-body scattering calculations using the valence electron FCI method with atomic cores represented using an effective core potential. It is shown that an accurate description of core-valence correlation is necessary for accurate calculations of molecular bond lengths, frequencies and dissociation energies. Interpolation between 1 2 A ab initio surface data points in a sparse grid is done using the global interpolant moving least squares method with a smooth radial data cutoff function included in the fitting weights and bivariate polynomials as a basis set. The Jahn-Teller splitting of the 1 2 E surface into the 1 2 A1 and 1 2 B2 states is investigated using a combination of both CASSCF and FCI levels of theory. Additionally, preliminary calculations of the 1 2 A surface are also presented using second order spin restricted open-shell Møller-Plesset perturbation theory.

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“…A detailed description of the computational method is given in our earlier papers [25,26] and is based on the description given by Czuchaj et al [27]. Therefore this section only summarizes the main aspects of the theory.…”

Section: Methodsmentioning

confidence: 99%

Theoretical study of highly-excited states of KRb molecule

2013

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Abstract:Semi-empirical adiabatic potential energy curves of highly excited states of the KRb molecule are calculated as a function of the internuclear distance R over a wide range from 3 to 150 0 . The diatomic molecule is treated as an effective two-electron system by using the large core pseudopotentials and core polarization potentials. All calculations are performed by using the nonrelativistic CASSCF/MRCI method with accurate basis set functions. The spectroscopic constants of the calculated electronic states agree well with experimental data, including the recent ones from Lee et al., and with available theoretical results. 31.15.Ar, 31.15.Ne, 31.25.Nj, 32.80.Pj, 33.80.Ps, 34.20.Cf PACS (2008): Keywords:configuration interaction method • adiabatic approximation • potential energy curves • spectroscopic parameters • pseudopotentials © Versita sp. z o.o.

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Calculation of adiabatic potentials of Li2

Cited by 49 publications

References 49 publications

A diabatic representation of the two lowest electronic states of Li3

A diabatic representation of the two lowest electronic states of Li3

Potential energy surface of the 1²A′ Li₂ + Li doublet ground state

Theoretical study of highly-excited states of KRb molecule

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Calculation of adiabatic potentials of Li2

Cited by 49 publications

References 49 publications

A diabatic representation of the two lowest electronic states of Li3

A diabatic representation of the two lowest electronic states of Li3

Potential energy surface of the 12A′ Li2 + Li doublet ground state

Theoretical study of highly-excited states of KRb molecule

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Potential energy surface of the 1²A′ Li₂ + Li doublet ground state