Heteroisotopic molecular behavior: the valence-bond theory of the positronium hydride

Rolim, Flávia; Moreira, Tathiana; Mohallem, José R.

doi:10.1590/s0103-97332004000600011

Cited by 15 publications

(12 citation statements)

References 16 publications

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“…This class of few-body systems includes the isotopomers of hydrogen molecule, muonium dimmer ( 2 µ ) as well as a series of bi-excitons; the latter had a long history with various applications in the solid state physics [17][18][19][20][21][22][23][24][25][26]. The real space structure of few-body exotic quantum systems has recently captured some attention [27][28][29][30][31][32][33][34][35][36] and is a particularly attractive field for the implementation of the TC-QTAIM analysis. Accordingly, the mass-dependence of the TC-QTAIM analysis is unraveled in this series of species in the whole considered mass spectrum, e e m m m 13 10 10 − = (m e stands for electron mass), which mimics in the two extremes the clamped nuclei hydrogen molecule and almost a positronium dimer.…”

mentioning

confidence: 99%

The two-component quantum theory of atoms in molecules (TC-QTAIM): the unified theory of localization/delocalization of electrons, nuclei, and exotic elementary particles

Goli

Shahbazian

2013

Theor Chem Acc

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In this contribution, pursuing our research program extending the atoms in molecules analysis into unorthodox domains, another key ingredient of the two-component quantum theory of atoms in molecules (TC-QTAIM) namely, the theory of localization/delocalization of quantum particles, is disclosed. The unified proposed scheme is able not only to deal with the localization/delocalization of electrons in/between atomic basins, but also to treat nuclei as well as exotic particles like positrons and muons equally. Based on the general reduced second order density matrices for indistinguishable quantum particles, the quantum fluctuations of atomic basins are introduced and then used as a gauge to quantify the localization/delocalization introducing proper indexes. The explicit mass-dependence of the proposed indexes is demonstrated and it is shown that a single localization/delocalization index is capable of being used for all kind of quantum particles regardless of their masses or charge content. For various non-Born-Oppenhiemer (non-BO) wavefunctions, including Hartree-product as well as singlet and triplet determinants, the indices are calculated and then employed to rationalize the localization/delocalization of particles in a series of fourbody model systems consist of two electrons and two positively charged particles with variable mass. The ab initio FV-MC_MO derived non-BO wavefunctions for the four-body series are used for a comprehensive computational TC-QTAIM analysis, including topological analysis as well as basin integrations, in a wide mass regime, (m e stands for electron mass), disclosing various traits in these series of species that are unique to the TC-QTAIM. On the other hand, it is demonstrated that in the large mass extreme the TC-QTAIM analysis reduces to the one performed within context of the orthodox QTAIM with two clamped positive particles revealing the fact that the TC-QTAIM encompasses the orthodox QTAIM as an asymptote. Finally, it is concluded that the proposed localization/delocalization scheme is capable of quantifying quantum tunneling of nuclei for systems containing delocalized protons. Such capability promises novel applications for the TC-QTAIM as well as its extended multi-component version (MC-QTAIM) introduced recently.

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mentioning

confidence: 99%

The two-component quantum theory of atoms in molecules (TC-QTAIM): the unified theory of localization/delocalization of electrons, nuclei, and exotic elementary particles

Goli

Shahbazian

2013

Theor Chem Acc

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“…[17], than the purely adiabatic Braz one, −0.7668 a.u. [15], both to be compared to the exact eigenvalue −0.7891 a.u. [19].…”

Section: Modelsmentioning

confidence: 99%

“…In face of this dilemma, a real change of paradigm is being considered: the idea of treating the positron as a pseudonucleus has eventually appeared in the literature, mostly in phenomenological or model calculations [11][12][13][14][15][16]. It has been proposed to go further and to perform a widespread adiabatic separation of motions of positively charged particles, positron plus nuclei, and electrons.…”

Section: Introductionmentioning

confidence: 99%

Is a Molecular Adiabatic Approximation Appropriate to Positronic Atoms and Molecules?

Mohallem

2008

Acta Phys. Pol. A

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The adiabatic approximation to positronic atoms and molecules was considered as an option to the computationally unfeasible methods that treat all particles in a common footing, in two different approaches communicated in the 37th PSPA. Here we present further assessment and comparison of the two approaches as a way of evaluating the potential of adiabatic or, as we found preferable, molecular approaches.

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“…Mohallem's method is limited to calculations in the basis of nucleuscentered atomic orbitals, as the Hamiltonian contains internuclear ␦ operators, but it is not a big limitation due to the popularity of the LCAO MO approach. It has been applied in the studies of interactions of positrons with normal matter, 7,8 where the effect of positron finite mass cannot be omitted. In the present work a different method to achieve the same goal will be proposed.…”

Section: Introductionmentioning

confidence: 99%

Modified adiabatic approximation: Charge asymmetry in HD+ and HD

Strasburger

2009

The Journal of Chemical Physics

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The modified adiabatic approximation is discussed, in which the interaction of electrons with nuclei is partitioned between the electronic and nuclear Hamiltonian, in order to simulate the finite nuclear mass effect. The proposed formalism is universal and can be used in calculations for molecules of any size. The effect of electron localization on the deuteron in vibrationally excited states of HD(+) and the permanent dipole moment of HD, typically both explained in terms of nonadiabatic couplings between g and u states, are well reproduced with this method.

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Heteroisotopic molecular behavior: the valence-bond theory of the positronium hydride

Cited by 15 publications

References 16 publications

The two-component quantum theory of atoms in molecules (TC-QTAIM): the unified theory of localization/delocalization of electrons, nuclei, and exotic elementary particles

The two-component quantum theory of atoms in molecules (TC-QTAIM): the unified theory of localization/delocalization of electrons, nuclei, and exotic elementary particles

Is a Molecular Adiabatic Approximation Appropriate to Positronic Atoms and Molecules?

Modified adiabatic approximation: Charge asymmetry in HD+ and HD

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