Adiabatic corrections to the energies of 50 typical medium size molecules containing H atoms

Mohallem, José R.; Gonçalves, Cristina P.; Moreira, Tathiana

doi:10.1016/j.cplett.2005.03.031

Cited by 5 publications

(10 citation statements)

References 16 publications

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“…The probable importance of DBOC for inner shell ionization processes was previously noted, 16,35 but we are unaware of any previous numerical demonstration of this.…”

Section: Resultsmentioning

confidence: 62%

“…The relationship of DBOC to the electronic kinetic energy has been noted before, and hence the DBOC is sometimes termed the 'electronic reduced mass effect'. 16,35 Mohallem et al 35 also found this effect to scale roughly proportional to the number of electrons, as far as molecules containing Te.…”

Section: Resultsmentioning

confidence: 93%

“…In this way, the calculation of the BO correction term in the Yb 2 molecule (or any heavy element molecules) may attract attention, but we need to incorporate relativity for these heavy-element calculations. At the nonrelativistic level, there are a number of reports related to DBOC methodological developments or applications. − In particular, note the work of Mohallem et al which probed adiabatic effects for elements up to Te (without considering relativistic effects). However, there was no open program to calculate the analytical BO correction for heavy element molecules including relativistic treatment.…”

Section: Introductionmentioning

confidence: 99%

“…At the nonrelativistic level, there are a number of reports related to DBOC methodological developments or applications. 7−35 In particular, note the work of Mohallem et al 35 which probed adiabatic effects for elements up to Te (without considering relativistic effects). However, there was no open program to calculate the analytical BO correction for heavy element molecules including relativistic treatment.…”

Section: Introductionmentioning

confidence: 99%

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Heavy Element Effects in the Diagonal Born–Oppenheimer Correction within a Relativistic Spin-Free Hamiltonian

et al. 2016

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Methodologies beyond the Born-Oppenheimer (BO) approximation are nowadays important to explain high precision spectroscopic measurements. Most previous evaluations of the BO correction are, however, focused on light-element molecules and based on a nonrelativistic Hamiltonian, so no information about the BO approximation (BOA) breakdown in heavy-element molecules is available. The present work is the first to investigate the BOA breakdown for the entire periodic table, by considering scalar relativistic effects in the Diagonal BO correction (DBOC). In closed shell atoms, the relativistic EDBOC scales as Z(1.25) and the nonrelativistic EDBOC scales as Z(1.17), where Z is the atomic number. Hence, we found that EDBOC becomes larger in heavy element atoms and molecules, and the relativistic EDBOC increases faster than nonrelativistic EDBOC. We have further investigated the DBOC effects on properties such as potential energy curves, spectroscopic parameters, and various energetic properties. The DBOC effects for these properties are mostly affected by the lightest atom in the molecule. Hence, in X2 or XAt molecule (X = H, Li, Na, K, Rb, and Cs) the effect of DBOC systematically decreases when X becomes heavier but in HX molecules, the effect of DBOC seems relatively similar among all the molecules.

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“…The probable importance of DBOC for inner shell ionization processes was previously noted, 16,35 but we are unaware of any previous numerical demonstration of this.…”

Section: Resultsmentioning

confidence: 62%

Section: Resultsmentioning

confidence: 93%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Heavy Element Effects in the Diagonal Born–Oppenheimer Correction within a Relativistic Spin-Free Hamiltonian

et al. 2016

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“…In one of them, the adiabatic corrections to the energies of 50 molecules have been evaluated at the MP2 level. 8 A single criticism on this scheme appeared in the literature showing that it predicts barrier heights for the H 2 + H reaction that are qualitatively different from those predicted by DBOC. 20 We connect this failure to a probable inadequacy of FNMC to singular points of the potential energy surfaces (the transition-state point in the case cited) where information about the energy derivatives relative to the nuclear coordinates may become important.…”

Section: Theorymentioning

confidence: 99%

Adiabatic Corrections to Density Functional Theory Energies and Wave Functions

et al. 2008

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The adiabatic finite-nuclear-mass-correction (FNMC) to the electronic energies and wave functions of atoms and molecules is formulated for density-functional theory and implemented in the deMon code. The approach is tested for a series of local and gradient corrected density functionals, using MP2 results and diagonal-Born-Oppenheimer corrections from the literature for comparison. In the evaluation of absolute energy corrections of nonorganic molecules the LDA PZ81 functional works surprisingly better than the others. For organic molecules the GGA BLYP functional has the best performance. FNMC with GGA functionals, mainly BLYP, show a good performance in the evaluation of relative corrections, except for nonorganic molecules containing H atoms. The PW86 functional stands out with the best evaluation of the barrier of linearity of H2O and the isotopic dipole moment of HDO. In general, DFT functionals display an accuracy superior than the common belief and because the corrections are based on a change of the electronic kinetic energy they are here ranked in a new appropriate way. The approach is applied to obtain the adiabatic correction for full atomization of alcanes C(n)H(2n+2), n = 4-10. The barrier of 1 mHartree is approached for adiabatic corrections, justifying its insertion into DFT.

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