Local ionization energy and local polarizability

Jin, Ping; Murray, Jane S.; Politzer, Peter

doi:10.1002/qua.10717

Cited by 45 publications

(32 citation statements)

References 60 publications

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“…More recently, an alternative procedure has been proposed to quantify localized ionization potentials and electron affinities. 39,40 For our model, we explored the scope of empirically derived effective donor and acceptor energies, EE occ and EE vac (see section Materials and Methods) to provide information about the site-specific readiness of the molecule to donate or accept electronic charge in the context of hydrogen bonding. Replacement of E HOMO and E LUMO by EE occ (r) and EE vac (r) thus yielded…”

Section: Polarizability Componentmentioning

confidence: 99%

Modeling the H bond donor strength of OH, NH, and CH sites by local molecular parameters

et al. 2008

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A quantum chemical model is introduced to predict the H-bond donor strength of monofunctional organic compounds from their ground-state electronic properties. The model covers -OH, -NH, and -CH as H-bond donor sites and was calibrated with experimental values for the Abraham H-bond donor strength parameter A using the ab initio and density functional theory levels HF/6-31G** and B3LYP/6-31G**. Starting with the Morokuma analysis of hydrogen bonding, the electrostatic (ES), polarizability (PL), and charge transfer (CT) components were quantified employing local molecular parameters. With hydrogen net atomic charges calculated from both natural population analysis and the ES potential scheme, the ES term turned out to provide only marginal contributions to the Abraham parameter A, except for weak hydrogen bonds associated with acidic -CH sites. Accordingly, A is governed by PL and CT contributions. The PL component was characterized through a new measure of the local molecular hardness at hydrogen, eta(H), which in turn was quantified through empirically defined site-specific effective donor and acceptor energies, EE(occ) and EE(vac). The latter parameter was also used to address the CT contribution to A. With an initial training set of 77 compounds, HF/6-31G** yielded a squared correlation coefficient, r(2), of 0.91. Essentially identical statistics were achieved for a separate test set of 429 compounds and for the recalibrated model when using all 506 compounds. B3LYP/6-31G** yielded slightly inferior statistics. The discussion includes subset statistics for compounds containing -OH, -NH, and active -CH sites and a nonlinear model extension with slightly improved statistics (r(2) = 0.92).

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Section: Polarizability Componentmentioning

confidence: 99%

Modeling the H bond donor strength of OH, NH, and CH sites by local molecular parameters

et al. 2008

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“…This is not true for molecules, however; their ionization energies vary over a much smaller range than do their volumes (and polarizabilities) 12, and there is no consistent mutual pattern. Molecular α show a good correlation with V alone 12–18, but not with I alone, although there is an overall tendency for α to increase as I decreases. The inclusion of I does have a beneficial effect; in earlier work, for a group of 29 molecules (Table I), α ∼ V was found to have R 2 = 0.960 and root mean square error = 0.76 Å 3 , whereas α ∼ V / I 1/2 had R 2 = 0.971 and root mean square error = 0.65 Å 3 12.…”

Section: Introductionmentioning

confidence: 96%

“…The fact that α correlates with both V and 1/ I 3 for atoms can be attributed to V and I being inversely related 2, 8–11. This is not true for molecules, however; their ionization energies vary over a much smaller range than do their volumes (and polarizabilities) 12, and there is no consistent mutual pattern. Molecular α show a good correlation with V alone 12–18, but not with I alone, although there is an overall tendency for α to increase as I decreases.…”

Section: Introductionmentioning

confidence: 97%

Computational prediction of relative group polarizabilities

Jin

Brinck

Murray

et al. 2003

Int J of Quantum Chemistry

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ABSTRACT:Earlier work has shown that molecular polarizabilities correlate well with the quantity V/I S,ave , where V is the volume of the molecule and I S,ave is the average value of the local ionization energy on its surface. We now extend this to group polarizabilities; we computed V/I S,ave for four common chemical groups (NO 2 , CH 3 , NH 2 , and OH) in a variety of molecules. The transferabilities of I S,ave , V, and V/I S,ave are examined, as well as the correlation between V/I S,ave and literature polarizabilities of CH 3 , NH 2 , and OH. This permits the value for NO 2 to be predicted (␣ ϭ 2.77 Å 3 ). The dependence of I S,ave , and therefore V/I S,ave , upon the remainder of the molecule is discussed.

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“…6-8 for reviews). They interpreted the functionĪ (r) = −¯ (r) as the average local ionization energy, that is, the average energy required to remove an electron at point r, and found that it provides useful information about molecular reactivity, 6-11 electronegativity, 12,13 polarizability, 3,14 and other properties. [6][7][8] In a parallel development, Nagy and co-workers 15-17 studied the concept of local temperature of electronic systems and showed that it is closely related to¯ KS (r), the average local KS orbital energy.…”

Section: Introductionmentioning

confidence: 99%

Average local ionization energy generalized to correlated wavefunctions

Ryabinkin

Staroverov

2014

The Journal of Chemical Physics

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The average local ionization energy function introduced by Politzer and co-workers [Can. J. Chem. 68, 1440 (1990)] as a descriptor of chemical reactivity has a limited utility because it is defined only for one-determinantal self-consistent-field methods such as the Hartree-Fock theory and the Kohn-Sham density-functional scheme. We reinterpret the negative of the average local ionization energy as the average total energy of an electron at a given point and, by rewriting this quantity in terms of reduced density matrices, arrive at its natural generalization to correlated wavefunctions. The generalized average local electron energy turns out to be the diagonal part of the coordinate representation of the generalized Fock operator divided by the electron density; it reduces to the original definition in terms of canonical orbitals and their eigenvalues for one-determinantal wavefunctions. The discussion is illustrated with calculations on selected atoms and molecules at various levels of theory.

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Local ionization energy and local polarizability

Cited by 45 publications

References 60 publications

Modeling the H bond donor strength of OH, NH, and CH sites by local molecular parameters

Modeling the H bond donor strength of OH, NH, and CH sites by local molecular parameters

Computational prediction of relative group polarizabilities

Average local ionization energy generalized to correlated wavefunctions

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