Population analysis in plane wave electronic structure calculations

Segall, Matthew D.; Pickard, Chris J.; Shah, Rajiv; Payne, Michael

doi:10.1080/00268979609482494

Cited by 178 publications

(149 citation statements)

References 7 publications

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“…In Table IV, the principal components of the Born effective charge tensors for an isolated chain and crystalline states of PPV, together with atomic charges obtained by Mulliken population 34 analyses, are presented. Note that we show the charges for symmetry-related atoms in the table.…”

Section: Born Effective Chargementioning

confidence: 99%

Ab initio dynamics study of poly-para-phenylene vinylene

Zheng

Clark

Tulip

et al. 2005

The Journal of Chemical Physics

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Use policyThe full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-pro t purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details. We present an ab initio dynamics investigation within a density-functional perturbation theory framework of the properties of the conjugated polymer poly-para-phenylene vinylene ͑PPV͒ in both the isolated chain and crystalline states. The calculated results show that for an isolated chain, most of the vibrational modes correspond to experimentally observed modes in crystalline PPV. However, additional hitherto unidentified modes have been observed in experiment and our calculations on crystalline material have allowed us to assign these. We also present the results of calculations of the polarizability and permittivity tensors of the material, which are in reasonable agreement with the typical values for conjugated polymers. Dynamical Born effective charges ͓S. Baroni, S. de Gironcoli, A. Dal Corso, and P. Giannozzi, Rev. Mod. Phys. 73, 515 ͑2001͔͒ are calculated and compared with atomic charges obtained from Mulliken population analysis ͓M. D. Segall, C. J. Pickard, R. Shah, and M. C. Payne, Mol. Phys. 89, 571 ͑1996͔͒ and we conclude that effective charges are more appropriate for use in the study of the dynamics of the system. Notable differences are found in the infrared-absorption spectra obtained for the isolated chain and crystalline states, which can be attributed to the differences in the crystalline packing effects, which clearly play a key role in influencing the lattice dynamics of PPV.

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Section: Born Effective Chargementioning

confidence: 99%

Ab initio dynamics study of poly-para-phenylene vinylene

Zheng

Clark

Tulip

et al. 2005

The Journal of Chemical Physics

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“…From the relaxed geometries of the monomer/clay models the surface coverage of the basal surfaces was calculated, and this was repeated for the trimers to give an indication of the differences that might be seen when using longer chains of polymers. The formation energies of the monomer/kaolinite models and the relative charges of the monomers and trimers using Mulliken analysis were also calculated [38][39][40][41]. …”

Section: Computer Simulation Modelsmentioning

confidence: 99%

Understanding Cationic Polymer Adsorption on Mineral Surfaces: Kaolinite in Cement Aggregates

Jacquet¹,

Geatches

Clark

et al. 2018

Minerals

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Abstract:We present a joint experimental and theoretical investigation into the adsorption of polycationic quaternary ammonium polymers on the clay mineral kaolinite. Within the cement and concrete manufacturing industries such polymers are used to improve the final product by inerting the adsorption capacity of the clay minerals for more expensive additives. The adsorption of the presently used polymer (FL22) was compared with both a similar variant, but without a hydroxyl group (Fl22mod) and uncharged polyvinyl alcohol (PVA). Experimental results show that adsorption of FL22 is higher than that of FL22mod at both pH 6 and at pH > 10 and that the adsorption of PVA is the highest. Theoretical density functional theory (DFT) results and simplified models consisting of the basal surfaces of kaolinite, with monomers of FL22, FL22mod and PVA gave monomer coverage per unit surface area of kaolinite, a comparison of the configurations of the relaxed models, formation energies and Mulliken charges. These results show that the polycationic polymers interact with the basal surfaces of kaolinite electrostatically, explaining the high affinity of these polymers for kaolinite surfaces in the experimental results. The hydroxyl groups of FL22 and PVA form hydrogen bonds with the basal surfaces of kaolinite in conditions of pH 6. The joint experimental and theoretical results suggest that, due to the presence of the hydroxyl group, the conformation of FL22 changes under pH, where at neutral pH it lies relatively flat to the kaolinite surfaces, but at higher pH, conformational changes of the polymer occur, thereby increasing the adsorbed quantity of FL22.

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“…To this end, a DFT calculation is performed which yields the electronic density and the Kohn-Sham wave functions. Partitioning schemes using projections of the Kohn-Sham wavefunctions onto localized atomic orbitals (Löwdin or Mulliken analysis, see, e.g., Segall et al (1996)) as well as schemes dealing with the electronic density (Hirshfeld or Bader analysis, see, e.g., Meister & Schwarz (1994)) have been employed in the context of graphene adsorbate systems. While ionically bond systems are likely well suited to be correctly described by this kind of charge transfer analysis, the interpretation of Mulliken, Bader or Hirshfeld charges in physisorbed graphene-impurity systems (Leenaerts et al, 2008) or strongly covalent systems (see section 3.2) can be ambiguous.…”

Section: Population Analysis and Partitioning Of The Electron Densitymentioning

confidence: 99%