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Willis B. Person

Other affiliations: Polish Academy of Sciences
Bio: Willis B. Person is an academic researcher from University of Florida. The author has contributed to research in topics: Infrared spectroscopy & Infrared. The author has an hindex of 41, co-authored 165 publications receiving 6122 citations. Previous affiliations of Willis B. Person include Polish Academy of Sciences.


Papers
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Journal ArticleDOI
TL;DR: In this paper, the rotational contributions of the mass-weighted squared effective charges (MWEED) to the infrared intensity of water molecules were analyzed in Cartesian coordinates.

12 citations

Journal ArticleDOI
TL;DR: In this paper, the infrared absorption spectrum of benzene in an HCl "matrix" (HCl :benzene mole ratio of about 10:1) is compared in both frequency and intensity with the spectrum of crystalline benzene and of "glassy" benzene.

12 citations

Journal ArticleDOI
TL;DR: In this article, the structure, force field, and vibrational [infrared and Raman] spectra of the 1-methyluracil monomer and its dimer with the cyclic N3H … OC4 hydrogen bonds were calculated at the B3LYP/6-31G(d,p) level.
Abstract: Density functional theory at the B3LYP/6-31G(d,p) level has been used to calculate the structure, force field, and vibrational [infrared (IR) and Raman] spectra of the 1-methyluracil monomer and its dimer with the cyclic N3H … OC4 hydrogen bonds. The experimental IR spectrum of the 1-methyluracil monomer isolated in a low-temperature Ar matrix and the IR and Raman spectra of its polycrystalline solid have been reinvestigated. The cyclic hydrogen bond for the calculated dimer is the same as that in the 1-methyluracil crystal. It appears that calculation at this level of theory does provide IR and Raman spectra closely resembling the corresponding experimental spectra. We were amazed to find that the agreement between the calculated spectrum of the dimer and the experimental spectrum of the crystalline solid is not worse than the agreement between the calculated spectrum of the monomer and the experimental spectrum of 1-methyluracil isolated in an Ar matrix. The results of calculation appear to be useful in the interpretation of the experimental spectra of the monomer and crystal. The close agreement found between the calculated and experimental spectra suggests that force constants and geometries of the monomer and dimer are also predicted well by the calculation at this level. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem, 2002

12 citations

Journal ArticleDOI
TL;DR: In this paper, the relationship between atomic polar tensors (APTs) and experimental infrared intensities is reviewed and the invariant known as the square of the effective charge on the αth atom and its relationship to the intensity sum is defined.

10 citations


Cited by
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Journal ArticleDOI
TL;DR: The mechanisms of tissue bonding to bioactive ceramics are beginning to be understood, which can result in the molecular design of bioceramics for interfacial bonding with hard and soft tissues.
Abstract: Ceramics used for the repair and reconstruction of diseased or damaged parts of the musculo-skeletal system, termed bioceramics, may be bioinert (alumina, zirconia), resorbable (tricalcium phosphate), bioactive (hydroxyapatite, bioactive glasses, and glass-ceramics), or porous for tissue ingrowth (hydroxyapatite-coated metals, alumina). Applications include replacements for hips, knees, teeth, tendons, and ligaments and repair for periodontal disease, maxillofacial reconstruction, augmentation and stabilization of the jaw bone, spinal fusion, and bone fillers after tumor surgery. Carbon coatings are thromboresistant and are used for prosthetic heart valves. The mechanisms of tissue bonding to bioactive ceramics are beginning to be understood, which can result in the molecular design of bioceramics for interfacial bonding with hard and soft tissues. Composites are being developed with high toughness and elastic modulus match with bone. Therapeutic treatment of cancer has been achieved by localized delivery of radioactive isotopes via glass beads. Development of standard test methods for prediction of long-term (20-year) mechanical reliability under load is still needed.

4,292 citations

Journal Article
TL;DR: The mechanisms of tissue bonding to bioactive ceramics are beginning to be understood, which can result in the molecular design of bioceramics for interfacial bonding with hard and soft tissues.
Abstract: Ceramics used for the repair and reconstruction of diseased or damaged parts of the musculo-skeletal system, termed bioceramics, may be bioinert (alumina, zirconia), resorbable (tricalcium phosphate), bioactive (hydroxyapatite, bioactive glasses, and glass-ceramics), or porous for tissue ingrowth (hydroxyapatite-coated metals, alumina). Applications include replacements for hips, knees, teeth, tendons, and ligaments and repair for periodontal disease, maxillofacial reconstruction, augmentation and stabilization of the jaw bone, spinal fusion, and bone fillers after tumor surgery. Carbon coatings are thromboresistant and are used for prosthetic heart valves. The mechanisms of tissue bonding to bioactive ceramics are beginning to be understood, which can result in the molecular design of bioceramics for interfacial bonding with hard and soft tissues. Composites are being developed with high toughness and elastic modulus match with bone. Therapeutic treatment of cancer has been achieved by localized delivery of radioactive isotopes via glass beads. Development of standard test methods for prediction of long-term (20-year) mechanical reliability under load is still needed.

4,213 citations

Journal ArticleDOI
TL;DR: In this paper, the authors present conformational energies for a molecular mechanical model (Parm99) developed for organic and biological molecules using the restrained electrostatic potential (RESP) approach to derive the partial charges.
Abstract: In this study, we present conformational energies for a molecular mechanical model (Parm99) developed for organic and biological molecules using the restrained electrostatic potential (RESP) approach to derive the partial charges. This approach uses the simple "generic" force field model (Parm94), and attempts to add a minimal number of extra Fourier components to the torsional energies, but doing so only when there is a physical justification. The results are quite encouraging, not only for the 34-molecule set that has been studied by both the highest level ab initio model (GVB/LMP2) and experiment, but also for the 55-molecule set for which high-quality experimental data are available. Considering the 55 molecules studied by all the force field models for which there are experimental data, the average absolute errors (AAEs) are 0.28 (this model), 0.52 (MM3), 0.57 (CHARMm (MSI)), and 0.43 kcal/mol (MMFF). For the 34-molecule set, the AAEs of this model versus experiment and ab initio are 0.28 and 0.27 kcal/mol, respectively. This is a lower error than found with MM3 and CHARMm, and is comparable to that found with MMFF (0.31 and 0.22 kcal/mol). We also present two examples of how well the torsional parameters are transferred from the training set to the test set. The absolute errors of molecules in the test set are only slightly larger than in the training set (differences of <0.1 kcal/mol). Therefore, it can be concluded that a simple "generic" force field with a limited number of specific torsional parameters can describe intra- and intermolecular interactions, although all comparison molecules were selected from our 82-compound training set. We also show how this effective two-body

3,748 citations

Journal ArticleDOI
TL;DR: An all atom potential energy function for the simulation of proteins and nucleic acids and the first general vibrational analysis of all five nucleic acid bases with a molecular mechanics potential approach is presented.
Abstract: We present an all atom potential energy function for the simulation of proteins and nucleic acids. This work is an extension of the CH united atom function recently presented by S.J. Weiner et al. J. Amer. Chem. Soc., 106, 765 (1984). The parameters of our function are based on calculations on ethane, propane, n−butane, dimethyl ether, methyl ethyl ether, tetrahydrofuran, imidazole, indole, deoxyadenosine, base paired dinucleoside phosphates, adenine, guanine, uracil, cytosine, thymine, insulin, and myoglobin. We have also used these parameters to carry out the first general vibrational analysis of all five nucleic acid bases with a molecular mechanics potential approach.

3,291 citations

Journal ArticleDOI
TL;DR: The specific advantages brought up by a design based on the use of the halogen bond will be demonstrated in quite different fields spanning from material sciences to biomolecular recognition and drug design.
Abstract: The halogen bond occurs when there is evidence of a net attractive interaction between an electrophilic region associated with a halogen atom in a molecular entity and a nucleophilic region in another, or the same, molecular entity. In this fairly extensive review, after a brief history of the interaction, we will provide the reader with a snapshot of where the research on the halogen bond is now, and, perhaps, where it is going. The specific advantages brought up by a design based on the use of the halogen bond will be demonstrated in quite different fields spanning from material sciences to biomolecular recognition and drug design.

2,582 citations