@article {2278,
title = {Accurate calculation of N1s and C1s core electron binding energies of substituted pyridines. Correlation with basicity and with Hammett substituent constants},
journal = {Journal of Molecular Structure-Theochem},
volume = {863},
number = {1-3},
year = {2008},
note = {ISI Document Delivery No.: 342NSTimes Cited: 6Cited Reference Count: 23Takahata, Yuji Wulfman, Carl E. Chong, Delano P.},
month = {Aug},
pages = {33-38},
type = {Article},
abstract = {Substituent shifts of the energetics of four related ionization processes of pyridines and benzoic acids (Fig. I) were investigated. The first process is core-electron ionization of gas-phase pyridines (Fig. 1A), while the second concerns gas-phase acid-base reaction between a substituted pyridine and a Conjugated acid (Fig. 1B), and the third and fourth processes are the acid dissociation of substituted benzoic acids in aqueous solution (Fig. 1C and in vacuum (Fig. 1D), respectively. Core-electron binding energies for the first process Were Calculated using density-functional theory with the scheme Delta E-KS (PW86x-PW91c/TZP+C-ret)//HF/6-31G*. Average absolute deviation of calculated core electron binding energy shifts at N atom in Substituted pyridines from experiment was 0.08 eV. The shift at N coincides highly with that at a ring carbon atom. The four shifts corresponding to the four processes shown in Figs. 1A-D correlate strongly with one another. with numerical values fairly close to each other when expressed in unit of electron volts. (C) 2008 Elsevier B.V. All rights reserved.},
keywords = {acid dissociation, BENZENE-DERIVATIVES, CEBE shifts, DENSITY-FUNCTIONAL CALCULATION, DFT, Hammett substituent (sigma) constant, ionization processes, PARAMETERS, pyridines, SHIFTS, SIGMA CONSTANTS, SPECTROSCOPY},
isbn = {0166-1280},
url = {://000258791400006},
author = {Takahata, Y. and Wulfman, C. E. and Chong, D. P.}
}
@article {1549,
title = {Geometry, solvent, and polar effects on the relationship between calculated core-electron binding energy shifts (Delta CEBE) and Hammett substituent (sigma) constants},
journal = {Journal of Molecular Structure-Theochem},
volume = {758},
number = {1},
year = {2006},
note = {ISI Document Delivery No.: 011GHTimes Cited: 7Cited Reference Count: 27},
month = {Jan},
pages = {61-69},
type = {Article},
abstract = {According to Lindberg et al. there exists an equation Delta CEBE=kappa sigma for substituted benzene derivatives. Core-electron binding energy shift (Delta CEBE) is the difference between the CEBE of a specific carbon in monosubstituted benzene derivatives (C6H5-Z) and in benzene (C6H5-H); K is related to a reaction constant and or is the experimental Hammett substituent constant. The object of the present work is to investigate geometry, solvent, and polar effects on Lindberg{\textquoteright}s equation using theoretically calculated ACEBE. The CEBEs were calculated using DFT within the scheme Delta E-KS (PW86x-PW91c/TZP + C-rel). The geometry has only little effect on the CEBE values. A regression relation between ACEBE and 0, takes the form Delta CEBE = kappa sigma-C with K congruent to 1.17 and C congruent to 0.17. We estimated 69 sigma constants in water that have not been presented in the literature. Theoretical resonance (sigma(R)) and inductive (sigma(I)) effects were calculated using Taft equations. ACEBE (R) and ACEBE (1) effects on ACEBE were also calculated using Taft-like equations. The quality of the correlation to the resonance is better than that to the inductive effect, in water. The regression quality in aqueous organic solvent is poorer than in water in both Lindberg and Taft equations. The solvent effect is greater on the resonance than on the inductive effect. (c) 2006 Elsevier B.V. All rights reserved.},
keywords = {25-DEGREES-C, ACCURATE, BENZENE-DERIVATIVES, benzenes, BENZOIC-ACIDS, CEBE shift, COMPILATION, DENSITY-FUNCTIONAL CALCULATION, DFF, Hammett sigma, IONIZATION, ISOLATED MOLECULES, LEAST-SQUARES, LFER, STRUCTURE-REACTIVITY PARAMETERS},
isbn = {0166-1280},
url = {://000235255700009},
author = {Segala, M. and Takahata, Y. and Chong, D. P.}
}
@article {1191,
title = {Ansatz for the evaluation of the relativistic contributions to core ionization energies in complex molecules involving heavy atoms},
journal = {International Journal of Quantum Chemistry},
volume = {104},
number = {4},
year = {2005},
note = {ISI Document Delivery No.: 948JFTimes Cited: 4Cited Reference Count: 468th European Workshop on Quantum Systems in Chemistry and Physics (QSCP 8)AUG 30-SEP 04, 2003Spetses Isl, GREECE},
month = {Sep},
pages = {397-410},
type = {Proceedings Paper},
abstract = {On the basis of numerical, ab initio Delta DF and Delta HF computations of 1s-core, 2s-core, and 2p-core ionization energies of atoms, from Li through Xe, an allometric empirical formula that was proposed for evaluating relativistic corrections (including QED effects) to nonrelativistic values is assessed for homogeneous sets of elements in the periodic table. The two coefficients involved in this formula are precisely determined for 1s-core ionization in the sets of atoms Be-Ne, Mg-Ar, Zn-Kr, and Cd-Xe; 2s-core ionization in the sets of atoms Mg-Ar, Zn-Kr, and Cd-Xe; and 2p-core ionization in the set Mg-Ar. It is shown that the medium relative error on the results obtained using this formula, with respect to those directly computed, decreases from a few percent to a few hundredths of 1\% when the depth of the ionized level increases. This formula could be used to include relativistic (and QED) corrections to results yielded by simpler, nonrelativistic calculations on complex molecules involving heavy atoms. (c) 2005 Wiley Periodicals, Inc.},
keywords = {1S, 2p core ionizations, 2S, allometric fits, and QED, contributions, DENSITY-FUNCTIONAL CALCULATION, ELECTRON BINDING-ENERGIES, HOLE STATES, relativistic, relaxation, SPECTRA, spin-orbit},
isbn = {0020-7608},
url = {://000230711300003},
author = {Maruani, J. and Kuleff, A. I. and Chong, D. P. and Bonnelle, C.}
}
@article {750,
title = {DFT calculation of core-electron binding energies},
journal = {Journal of Electron Spectroscopy and Related Phenomena},
volume = {133},
number = {1-3},
year = {2003},
note = {ISI Document Delivery No.: 754ZWTimes Cited: 40Cited Reference Count: 70},
month = {Nov},
pages = {69-76},
type = {Article},
abstract = {A total of 59 core-electron binding energies (CEBEs) were studied with the Amsterdam Density Functional Program (ADF) program and compared with the observed values. The results indicate that a polarized triple-zeta basis set of Slater-type orbitals is adequate for routine assessment of the performance of each method of computation. With such a basis set, seven density functionals were tested. In addition, the performance of 21 energy density functionals were computed from the density calculated with the statistical average of orbital potentials (SAOP). Among all the choices tested, the best density functional for core-electron binding energies of C to F turns out to be the combination of Perdew-Wang (1986) functional for exchange and the Perdew-Wang (1991) functional for correlation, confirming earlier studies based on contracted Gaussian-type orbitals. For this best functional, five Slater-type orbital basis sets were examined, ranging from polarized double-zeta quality to the largest set available in the ADF package. For the best functional with the best basis set, the average absolute deviation (AAD) of the calculated value from experiment is only 0.16 eV (C) 2003 Elsevier B.V. All rights reserved.},
keywords = {ADF, BASIS-SETS, CEBE, CHEMICAL-SHIFTS, CONJUGATED, core-electron binding energy, CORRECT ASYMPTOTIC-BEHAVIOR, DENSITY-FUNCTIONAL CALCULATION, DFF, ESCA, EXCHANGE-ENERGY, GENERALIZED GRADIENT APPROXIMATION, MOLECULAR CALCULATIONS, MOLECULES, PHOTOELECTRON-SPECTROSCOPY, X-RAY-EMISSION, XPS},
isbn = {0368-2048},
url = {://000187364200010},
author = {Takahata, Y. and Chong, D. P.}
}
@article {770,
title = {sigma-bonded metal carbonyl cations and their derivatives: Syntheses and structural, spectroscopic, and bonding principles},
journal = {Organometallics},
volume = {22},
number = {18},
year = {2003},
note = {ISI Document Delivery No.: 716AGTimes Cited: 22Cited Reference Count: 150},
month = {Sep},
pages = {3612-3633},
type = {Review},
abstract = {Homoleptic sigma-bonded metal carbonyl cations (sigma-carbonyls) and their derivatives have grown in recent years into a large subgroup of mononuclear metal carbonyl complexes. They are at present formed by 17 elements, including the post transition metal mercury. Most are generated in superacids: the Lewis superacid SbF5 and the conjugate Bronsted-Lewis superacid HF-SbF5. Thermally stable salts are formed with the superacid anions [Sb2F11](-) and [SbF6](-). Many of the cations are superelectrophilic, with metals in oxidation states of +2 or +3. Three different synthetic routes are developed: reductive (A) or solvolytic carbonylations (B) and oxidative methods (C). Considerable progress has been made by replacing the Lewis superacid SbF5 as reaction medium by the conjugate Bronsted-Lewis superacid HF-SbF5. This allows reactions to proceed faster in a homogeneous phase and to produce crystalline materials. In total 27 mostly recent molecular structures have been obtained, including that of [Ir(CO)(6)] [SbF6](3)(.)4HF, the first HF solvate with one of the HF molecules coordinated in an isotridentate mode to three carbon atoms of the cation. Due to the electrophilic nature of the carbonyl carbon in fluoroantimonate salts of metal carbonyl cations, extended structures are formed via significant interionic C{\textendash}- F contacts. A new a-bonded carbonyl, (CF3)(3)BCO, which has been fully characterized, expands the existence range of metal carbonyl cations to group 13. The large amount of spectroscopic and structural information accumulated is used to present a conceptually simple bonding model.},
keywords = {CONCENTRATED SULFURIC-ACID, DENSITY-FUNCTIONAL CALCULATION, EFFECTIVE IONIC-RADII, HSO3F-SBF5, LEWIS SUPERACID, MAS-NMR-SPECTRA, MOLECULAR-STRUCTURE, NUCLEAR-MAGNETIC-RESONANCE, VIBRATIONAL-SPECTRA, WEAKLY COORDINATING ANIONS, X-RAY},
isbn = {0276-7333},
url = {://000185006200002},
author = {Willner, H. and Aubke, F.}
}
@article {349,
title = {DFT calculations of core-electron binding energies of the peptide bond},
journal = {Journal of Physical Chemistry A},
volume = {106},
number = {2},
year = {2002},
note = {ISI Document Delivery No.: 513ANTimes Cited: 24Cited Reference Count: 39},
month = {Jan},
pages = {356-362},
type = {Article},
abstract = {Although an efficient DFT method using the generalized transition-state model to calculate core-electron binding energies had been successfully applied to over 200 cases, with an average absolute deviation of only 0.21 eV from experiment, a new DeltaE(KS)(PW86-PW91)/cc-pCVTZ model based on total Kohn-Sham energy difference was recently developed. Not only was the model error-free, but also the average absolute deviation for 32 cases studied was found to be 0.15 eV. In this study, we first confirm the excellent performance of such a DeltaE(KS) approach with 46 new cases, with the result that the average absolute deviation from experiment for the 78 cases remains at 0.15 eV. With such consistent accuracy, this new method is applied to the peptide bond. The model molecules studied in this work include formamide, N-methylformamide, N,N-dimethylformamide, acetamide, N-methylacetamide, N,N-dimethylacetamide, and two model dipeptides, one cyclic and one acyclic. The difference in the computed nitrogen core-electron binding energy between the two model dipeptides is found to be 0.85 eV, several times our average absolute deviation. This may be of interest to other workers studying other aspects of the peptide bond.},
keywords = {AB-INITIO CALCULATIONS, ACCURATE, APPROXIMATION, DENSITY-FUNCTIONAL CALCULATION, DIFFRACTION, DIKETOPIPERAZINE, EXCHANGE-ENERGY, GAS, MOLECULAR-STRUCTURE, ZETA BASIS-SET},
isbn = {1089-5639},
url = {://000173355900019},
author = {Chong, D. P. and Aplincourt, P. and Bureau, C.}
}
@article {5058,
title = {Analysis of XPS and XES of diamond and graphite by DFT calculations using model molecules},
journal = {Journal of Computational Chemistry},
volume = {22},
number = {1},
year = {2001},
note = {ISI Document Delivery No.: 384EGTimes Cited: 6Cited Reference Count: 31},
month = {Jan},
pages = {102-108},
type = {Article},
abstract = {X-ray photoelectron and emission spectra (XPS and XES) of diamond and graphite have been analyzed by deMon density-functional theory (DFT) calculations using the model adamantane derivative (C10H12(CH3)(4)) and pyrene (C16H10) molecules, respectively. The theoretical valence photoelectron and C K alpha X-ray emission spectra for the allotrope are in good accordance with the experimental ones. The combined analysis of the valence XPS and C K alpha XES enables us to divide the valence electronic distribution into the individual contributions for p sigma-, and p pi -bonding MOs of the diamond and graphite, respectively. (C) 2000 John Wiley \& Sons, Inc.},
keywords = {APPROXIMATION, carbon allotrope, combined analysis of XPS and XES, DENSITY-FUNCTIONAL CALCULATION, DFT calculations, ELECTRON BINDING-ENERGIES, POLYMERS, RAY PHOTOELECTRON-SPECTRA, SILICON},
isbn = {0192-8651},
url = {://000165929000009},
author = {Endo, K. and Koizumi, S. and Otsuka, T. and Suhara, M. and Morohasi, T. and Kurmaev, E. Z. and Chong, D. P.}
}
@article {4894,
title = {Theoretical X-ray photoelectron spectra of polymers by deMon DFT calculations using the model dimers},
journal = {Journal of Molecular Structure},
volume = {522},
year = {2000},
note = {ISI Document Delivery No.: 305GFTimes Cited: 12Cited Reference Count: 60},
month = {Apr},
pages = {47-60},
type = {Article},
abstract = {Core-electron spectra of 15 polymers [(CH2CH2)(n) (PE), (CH2CH(CH3))(n) (PP), (CH2CH2NH)(n) (PEI), (CH2CH2O)(n) (PEG), (CH2CH(OCH3))(n) (PVME), (CH2CHF)(n) (PVF), (CH2CF2)(n) (PVDF), (CF2CF2)(n) (PTFE), (CH2CH(CN))(n) (PAN), (CH2C(CH3)(CN))(n) (PMAN), (CH2CH2S)(n) (PETHS), (CH2CHCl)(n) (PVC), (CH2CCl2)(n) (PVDC), (Si(CH3)(2))(n) (PDMS), (Si(CH3)(2)O)(n) (PDMSO)], and valence photoelectron spectra (XPS) of the six polymers (PP, PEI, PAN, PMAN, PVME, PTFE) were obtained by deMon density-functional theory (DFT) calculations using the model dimers. The core-electron spectra were simulated with the Gaussian lineshape functions with fixed linewidths of 0.5, and 1.0 eV for each C1sd, and (N1s, O1s, F1s) MO value, respectively, and calculated Al-K alpha Valence photoelectron spectra were obtained using Gaussian lineshape functions of an approximate linewidth (0.08I(k)): I-k(I-FL) = I-k{\textquoteright} - WD, as indicated in previous works. The vertical ionization potential I-k{\textquoteright} and each core-electron binding energy (CEBE) were calculated by restricted generalized diffuse ionization (rGDI) and unrestricted generalized transition-state (uGTS) models, respectively. The theoretical core-electron spectra showed better agreement with the experimental ones of the polymers than those due to Koopmans{\textquoteright} theorem. The difference between the calculated and the experimental CEBEs reflected the reasonable WDs of the polymers. (C) 2000 Elsevier Science B.V. All rights reserved.},
keywords = {C1S SPECTRA, core-electron spectra, deMon DFT calculations, DENSITY-FUNCTIONAL CALCULATION, ELECTRON-BINDING-ENERGIES, LOCAL-DENSITY, MOLECULES, POLY(METHYL METHACRYLATE), POLY(VINYL ALCOHOL), POLYMERS, SEMIEMPIRICAL MO THEORY, VALENCE-BAND, XPS CORE},
isbn = {0022-2860},
url = {://000086530500004},
author = {Otsuka, T. and Endo, K. and Suhara, M. and Chong, D. P.}
}
@article {4318,
title = {Analysis of X-ray photoelectron spectra of silicon-based polymers by deMon density functional calculations using model molecules},
journal = {Polymer Journal},
volume = {30},
number = {2},
year = {1998},
note = {ISI Document Delivery No.: ZD180Times Cited: 15Cited Reference Count: 40},
pages = {142-148},
type = {Article},
abstract = {The X-ray photoelectron spectra (XPS) of seven silicon-based polymers[ (-Si(CH3)(2)-)(n) (PDMS), (-Si(C6H5)(CH3)-)(n) (PMPS), (-Si(n-C6H13)(2)-)(n) (PDHS), (-Si(CH3)(2)-O-)(n) (PDMSO), (-Si(C6H5)(CH3)-O)(n) (PMPSO), (-Si(CH3)(C6H5)-CH2-)(n) (PMPSM), and (-Si(C6H5)(2)-CH2-)(n) (PDPSM)] in XPS were analyzed by deMon density-functional calculations using model molecules. Calculated Al-K-infinity valence photoelectron spectra were obtained using Gaussian lineshape functions of an approximate linewidth (0.10I(k)): I-k=I-k-WD, as in previous works. The vertical ionization potential I-k was calculated by restricted diffuse ionization (rDI) model. The theoretical spectra showed good agreement with the observed spectra of the polymers between 0-40eV. The core-electron binding energies (CEBEs) of Cls, Ols and Si2p of the model molecules were calculated by unrestricted generalized-state (uGTS) models. The difference between calculated and the observed CEBEs for Cls reflected WDs of the polymers.},
keywords = {APPROXIMATION, BEHAVIOR, DENSITY-FUNCTIONAL CALCULATION, ELECTRON BINDING-ENERGIES, electronic state, Fermi level, LOCAL-DENSITY, POLY(METHYLPHENYL)SILANE, POLYSILANE, silicon-based polymer, X-ray photoelectron spectra},
isbn = {0032-3896},
url = {://000072659400013},
author = {Kuroki, S. and Endo, K. and Maeda, S. and Chong, D. P. and Duffy, P.}
}
@article {3916,
title = {Recent advances in the practical and accurate calculation of core and valence XPS spectra of polymers: from interpretation to simulation?},
journal = {Nuclear Instruments \& Methods in Physics Research Section B-Beam Interactions with Materials and Atoms},
volume = {131},
number = {1-4},
year = {1997},
note = {ISI Document Delivery No.: YC279Times Cited: 5Cited Reference Count: 712nd International Symposium on Ionizing Radiation and Polymers (IRaP 96)NOV 03-08, 1996GUADELOUPE, FRANCECEA Saclay, DSM DRECAM, Univ Antilles Guyane, Int Atom Energy Agcy, Inst Oberflachenmodifizierung},
month = {Aug},
pages = {1-12},
type = {Proceedings Paper},
abstract = {Core and valence X-ray Photoelectron Spectroscopies (XPS) are routinely used to obtain information on the chemical composition, bonding and homogeneity of polymer surfaces. In spite of their apparent conceptual simplicity, Core and Valence Electron Binding Energies (CEBEs and VEBEs) a few electron-volts (eV) or fractions of an eV apart are difficult to interpret. We present some results obtained with various recent theoretical. approaches. An emphasis is made on a procedure based on the Density Functional Theory (DFT) that enables the calculation of CEBEs and VEBEs which are in remarkable agreement with experiment. The method has been tested on numerous small (3-6 atoms) to fairly large (15-25 atoms) molecules, and shows an average absolute deviation with experiment of only 0.20 eV for CEBEs and 0.30 eV for VEBEs, i.e. compatible with the resolution of the best XPS experiments carried out at the moment. Besides the quality of its predictions, the procedure takes advantage of the speed and CPU time scaling of DFT as a function of system size: it is computationally tractable, even for surprisingly large systems such as polymers, and may be an interesting accurate alternative to interpret and simulate XPS-probing on real systems, We illustrate the usefullness and pitfalls of this approach in fundamental as well as applied fields such as in the study of Polyacrylonitrile (PAN), Polytetrafluoroethylene (PTFE), Polyvinyldifluoride (PVdF) and gamma-Aminopropyltriethoxysilane (gamma-APS, an adhesion promoter). (C) 1997 Elsevier Science B.V.},
keywords = {DENSITY-FUNCTIONAL CALCULATION, ELECTRON BINDING-ENERGIES, ESCA, GREEN-FUNCTION, IONIZATION-POTENTIALS, MO METHOD, MODEL MOLECULES, POLYACRYLONITRILE, POLYETHYLENE LAMELLAE, RAY PHOTOELECTRON-SPECTROSCOPY},
isbn = {0168-583X},
url = {://A1997YC27900005},
author = {Bureau, C. and Chong, D. P. and Endo, K. and Delhalle, J. and Lecayon, G. and LeMoel, A.}
}