H/D isotope effect on structures, binding energies, and basis set superposition errors in F−(H2O)  (n= 1–3) clusters

Udagawa, Taro; Ishimoto, Takayoshi; Tachikawa, Masanori

doi:10.1016/j.chemphys.2014.07.014

Cited by 6 publications

(4 citation statements)

References 17 publications

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“…For quantitative discussion, nuclear orbital should be expanded by a suitable number of nuclear basis functions, and electron–nucleus and nucleus–nucleus correlation effects should be evaluated. However, we have already demonstrated that H/D isotope effect can be adequately analyzed by MC_MO‐MP2 calculations, in which only electron–electron correlation effect is taken account and only single s ‐type GTF is adopted as the nuclear basis function . We first performed the geometry optimization of the systems with the conventional MP2/6‐311G** level of calculation and confirmed that the optimized geometries correspond to stable structures by vibrational harmonic frequency calculations.…”

Section: Methodsmentioning

confidence: 71%

“…Consequently, our methods can conveniently reproduce the H/D GIEs, since electronic wavefunction obtained in multicomponent calculations directly reflects the difference of nuclear quantum nature of light nuclei. We have successfully revealed the H/D isotope effects on geometries, interaction energies, rate constants, and various properties in several HB systems with the aid of MC_MO and MC_DFT methods …”

Section: Introductionmentioning

confidence: 99%

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H/D isotope effect on charge-inverted hydrogen-bonded systems: Systematic classification of three different types in H₃XH^…YH₃(X = C, Si, or Ge, and Y = B, Al, or Ga) with multicomponent calculation

Udagawa

Tachikawa

2015

J. Comput. Chem.

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Three different H/D isotope effect in nine H3 XH(D)···YH3 (X = C, Si, or Ge, and Y = B, Al, or Ga) hydrogen-bonded (HB) systems are classified using MP2 level of multicomponent molecular orbital method, which can take account of the nuclear quantum nature of proton and deuteron. First, in the case of H3 CH(D)···YH3 (Y = B, Al, or Ge) HB systems, the deuterium (D) substitution induces the usual H/D geometrical isotope effect such as the contraction of covalent R(C-H(D)) bonds and the elongation of intermolecular R(H(D)···Y) and R(C···Y) distances. Second, in the case of H3 XH(D)···YH3 (X = Si or Ge, and Y = Al or Ge) HB systems, where H atom is negatively charged called as charge-inverted hydrogen-bonded (CIHB) systems, the D substitution leads to the contraction of intermolecular R(H(D)···Y) and R(X···distances. Finally, in the case of H3 XH(D)···BH3 (X = Si or Ge) HB systems, these intermolecular R(H(D)···Y) and R(X···Y) distances also contract with the D substitution, in which the origin of the contraction is not the same as that in CIHB systems. The H/D isotope effect on interaction energies and spatial distribution of nuclear wavefunctions are also analyzed.

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Section: Methodsmentioning

confidence: 71%

Section: Introductionmentioning

confidence: 99%

H/D isotope effect on charge-inverted hydrogen-bonded systems: Systematic classification of three different types in H₃XH^…YH₃(X = C, Si, or Ge, and Y = B, Al, or Ga) with multicomponent calculation

Udagawa

Tachikawa

2015

J. Comput. Chem.

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“…53 for a coverage of the relevant literature before 2011). [39][40][41][42][43][44][45][46][47][48][49][50][51][52][53] This success is by part understandable based on the fact that the electronnucleus correlation in comparison to the electron-electron correlation is seemingly local by its nature and relatively insensitive to its environment. Thus, while the mentioned ab initio procedures are probably unable to reproduce absolute values of the nuclear vibrational frequencies, they may reproduce the correct trends in isotopically substituted series of molecules.…”

Section: Introductionmentioning

confidence: 99%

Toward a muon-specific electronic structure theory: effective electronic Hartree–Fock equations for muonic molecules

Rayka

Goli

Shahbazian

2018

Phys. Chem. Chem. Phys.

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An effective set of Hartree-Fock (HF) equations are derived for electrons of muonic systems, i.e., molecules containing a positively charged muon, conceiving the muon as a quantum oscillator, which are completely equivalent to the usual two-component HF equations used to derive stationary states of the muonic molecules. In these effective equations, a non-Coulombic potential is added to the orthodox coulomb and exchange potential energy terms, which describes the interaction of the muon and the electrons effectively and is optimized during the self-consistent field cycles. While in the two-component HF equations a muon is treated as a quantum particle, in the effective HF equations it is absorbed into the effective potential and practically transformed into an effective potential field experienced by electrons. The explicit form of the effective potential depends on the nature of muon's vibrations and is derivable from the basis set used to expand the muonic spatial orbital. The resulting effective Hartree-Fock equations are implemented computationally and used successfully, as a proof of concept, in a series of muonic molecules containing all atoms from the second and third rows of the Periodic Table. To solve the algebraic version of the equations muon-specific Gaussian basis sets are designed for both muon and surrounding electrons and it is demonstrated that the optimized exponents are quite distinct from those derived for the hydrogen isotopes. The developed effective HF theory is quite general and in principle can be used for any muonic system while it is the starting point for a general effective electronic structure theory that incorporates various types of quantum correlations into the muonic systems beyond the HF equations.

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“…43,44,[83][84][85][86][87][88][89] Both the MP2, [90][91][92][93] and the CC, [94][95][96][97] theories have been extended also for the multi-component systems and particularly, the multi-component MP2 method has been applied in many recent studies. [98][99][100][101][102][103][104][105][106][107][108][109] In the multi-component MP2 formalism where the NEO-MP2 is a typical exmaple, 90 the two separate correction terms for the muonic systems include the second order ee and μe correlation energies and is called NEO-MP2(ee+µe). Although the formalism is theoretically sound, in computational studies the μe correction term does not always yield reliable results (Goli and Shahbazian, unpublished results), casting some doubt on whether the NEO-MP2 is always a proper tool for recovering the μe correlation energy.…”

Section: Theorymentioning

confidence: 99%

Developing effective electronic-only coupled-cluster and Møller–Plesset perturbation theories for the muonic molecules

Goli

Shahbazian

2018

Phys. Chem. Chem. Phys.

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Recently we have proposed an effective Hartree-Fock (EHF) theory for the electrons of the muonic molecules that is formally equivalent to the HF theory within the context of the nuclear-electronic orbital theory [Phys. Chem. Chem. Phys., 2018, 20, 4466]. In the present report we extend the muon-specific effective electronic structure theory beyond the EHF level by introducing the effective second order Møller-Plesset perturbation theory (EMP2) and the effective coupled-cluster theory at single and double excitation levels (ECCSD) as well as an improved version including perturbative triple excitations (ECCSD(T)). These theories incorporate electron-electron correlation into the effective paradigm and through their computational implementation, a diverse set of small muonic species is considered as a benchmark at these post-EHF levels. A comparative computational study on this set demonstrates that the muonic bond length is in general non-negligibly longer than corresponding hydrogenic analogs. Next, the developed post-EHF theories are applied for the muoniated N-heterocyclic carbene/silylene/germylene and the muoniated triazolium cation revealing the relative stability of the sticking sites of the muon in each species. The computational results, in line with previously reported experimental data demonstrate that the muon generally prefers to attach to the divalent atom with carbeneic nature. A detailed comparison of these muonic adducts with the corresponding hydrogenic adducts reveals subtle differences that have already been overlooked.

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H/D isotope effect on structures, binding energies, and basis set superposition errors in F−(H2O) (n= 1–3) clusters

Cited by 6 publications

References 17 publications

H/D isotope effect on charge-inverted hydrogen-bonded systems: Systematic classification of three different types in H₃XH^…YH₃(X = C, Si, or Ge, and Y = B, Al, or Ga) with multicomponent calculation

H/D isotope effect on charge-inverted hydrogen-bonded systems: Systematic classification of three different types in H₃XH^…YH₃(X = C, Si, or Ge, and Y = B, Al, or Ga) with multicomponent calculation

Toward a muon-specific electronic structure theory: effective electronic Hartree–Fock equations for muonic molecules

Developing effective electronic-only coupled-cluster and Møller–Plesset perturbation theories for the muonic molecules

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H/D isotope effect on structures, binding energies, and basis set superposition errors in F−(H2O) (n= 1–3) clusters

Cited by 6 publications

References 17 publications

H/D isotope effect on charge-inverted hydrogen-bonded systems: Systematic classification of three different types in H3XH…YH3(X = C, Si, or Ge, and Y = B, Al, or Ga) with multicomponent calculation

H/D isotope effect on charge-inverted hydrogen-bonded systems: Systematic classification of three different types in H3XH…YH3(X = C, Si, or Ge, and Y = B, Al, or Ga) with multicomponent calculation

Toward a muon-specific electronic structure theory: effective electronic Hartree–Fock equations for muonic molecules

Developing effective electronic-only coupled-cluster and Møller–Plesset perturbation theories for the muonic molecules

Contact Info

Product

Resources

About

H/D isotope effect on charge-inverted hydrogen-bonded systems: Systematic classification of three different types in H₃XH^…YH₃(X = C, Si, or Ge, and Y = B, Al, or Ga) with multicomponent calculation

H/D isotope effect on charge-inverted hydrogen-bonded systems: Systematic classification of three different types in H₃XH^…YH₃(X = C, Si, or Ge, and Y = B, Al, or Ga) with multicomponent calculation