Made available in DSpace on 2016-08-18T18:19:28Z (GMT). No. of bitstreams: 1 Mauro Bogea Pereira.pdf: 2672209 bytes, checksum: 6ffa34d37be7c980ea311a6504843760 (MD5) Previous issue date: 2011-04-28 / FUNDAÇÃO SOUSÂNDRADE DE APOIO AO DESENVOLVIMENTO DA UFMA / In this work the electronic and structural properties of the hetero-nanotube bundles, composed of a CNT (6,0) encapsulated in a BNNT (14,0) (CNT (6,0)@BNNT (14,0)) and a BNNT (6,0) encapsulated in a CNT (14,0) (BNNT(6,0)@CNT (14,0)), under hydrostatic pressure. For this, we applied density functional theory and generalized gradient approximation to the exchange and correlation term, as implemented in SIESTA code. We observed that structural changes occur when pressure is applied. For the CNT(6,0)@BNNT(14,0) these changes begin when the pressure is close to 1,0 GPa for the outer tube, while for the inner tube the changes are observed around 10,0 GPa. In the case of BNNT(6,0)@CNT(14,0) the structure begins to be modified when the applied pressure is close to 3,0 GPa. The analysis of the band structure shown that the metallic character of the CNT(6,0)@BNNT(14,0) and the semiconductor character of the BNNT(6,0)@CNT(14,0) did not change when the pressure is applied. / Neste trabalho foram estudadas as propriedades eletrônicas e estruturais de bundles de hetero-nanotubos, compostos por um CNT (6,0) encapsulado em um BNNT (14,0) (CNT(6,0)@BNNT(14,0)) e por um BNNT (6,0) encapsulado em um CNT (14,0) (BNNT(6,0)@CNT(14,0)), submetidos a pressão hidrostática. Para tanto, fizemos uso da teoria do funcional da densidade e da aproximação do gradiente generalizado para tratar o termo de troca e correlação, implementados no programa computacional SIESTA. Observou-se que ocorrem alterações estruturais nos bundles a medida que a pressão é aplicada. Para o CNT(6,0)@BNNT(14,0) estas alterações têm início a pressões próximas de 1,0 GPa para o tubo externo, enquanto que para o tubo interno as alterações só começam a ser observadas próximo de 10,0 GPa. No caso do BNNT(6,0)@CNT(14,0) a estrutura só começa a ser modificada quando o pressão aplicada é próxima de 3,0 GPa. A análise da estrutura de bandas de energia das duas estruturas mostrou que o caráter eletrônico, metálico para os CNT(6,0)@BNNT(14,0) e semicondutor para os BNNT(6,0)@CNT(14,0), mantêm-se estáveis mesmo para os maiores valores de pressão aplicados.

Submitted by Celso Magalhaes (celsomagalhaes@ufrrj.br) on 2017-05-30T17:17:07Z No. of bitstreams: 1 2015 - Than?zia Ferraz Santos.pdf: 1742658 bytes, checksum: 07706cbaaa52be04cb7ec04d0d453fa2 (MD5) / Made available in DSpace on 2017-05-30T17:17:07Z (GMT). No. of bitstreams: 1 2015 - Than?zia Ferraz Santos.pdf: 1742658 bytes, checksum: 07706cbaaa52be04cb7ec04d0d453fa2 (MD5) Previous issue date: 2015-08-28 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico - CNPq / In this work, potential energy surfaces for the reactions of hydroxyl radical and 2,5-dimethylfuran were studied using the Density Functional Theory. The stationary points, such as reactants, pre-barrier complex, transition states and products were located at BHandHLYP/aug-cc-pVDZ and M06-2X-cc-pVDZ levels by geometry optimization, followed by the calculations of vibrational frequencies. Single point calculations using CCSD(T) were also explored. Thermodynamics properties of enthalpy, entrophy and Gibbs free energies have been determinated at 298,15 K within the conventional equations of Statistical Thermodynamics. The results suggest different addition mechanisms, since an analysis of the potential energy surface (PES) in BHandHLYP/ aug-cc-pVDZ points to paths going through a pi-type intermediary, while in M06-2X/aug-cc-pVDZ the intermediary would have a sigma-type interaction. About the abstraction reactions, only the PES obtained in M06-2X/aug-cc-pVDZ level points to the formation of a pre-barrier complex. The rate coefficients have been determined on the basis of the Variational Transition State Theory, with the kcvt program. The coefficient obtained at CCSD(T)/aug-cc-pVDZ//BHandHLYP/aug-cc-pVDZ for the mechanism which includes the participation of ?-PC is ???????=48,4?10?11, cm? molec-1 s-1, approximately 4 times higher than the experimental rate coefficient. Deviations of this magnitude are considered satisfactory in theoretical calculation of kinetic parameters. Addition of OH should be the main degradation pathway for furan and its derivatives, during daytime. Moreover, it was possible to clarify the effect of the formation of pre-barrier complexes in the reactions between DMF and OH radicals and propose rate coefficients in the high temperature region, which can be applied in combustion studies / Neste trabalho, as superf?cies de energia potencial para as rea??es do radical hidroxila (OH) com o 2,5-dimetilfurano (DMF) foram estudadas em detalhes, utilizando a Teoria do Funcional de Densidade. Pontos estacion?rios como reagentes, complexos pr?-barreira, estados de transi??o e produtos foram localizados por procedimentos de otimiza??o de geometria, acompanhado do c?lculo das frequ?ncias vibracionais, em n?veis BHandHLYP/aug-cc-pVDZ e M06-2X/aug-cc-pVDZ. C?lculos single point a partir da metodologia coupled-cluster com simples e duplas excita??es com tratamento perturbativo das triplas conectadas, CCSD(T), tamb?m foi explorado. Propriedades termodin?micas de entalpia, entropia e energia livre de Gibbs foram calculadas a 298,15 K atrav?s das equa??es da Termodin?mica Estat?stica. Os resultados sugerem mecanismos de adi??o diferentes, j? que uma an?lise da superf?cie de energia potencial (SEP) em BHandHLYP/aug-cc-pVDZ aponta para caminhos passando por um intermedi?rio do tipo pi, enquanto em M06-2X/aug-cc-pVDZ o intermedi?rio seria do tipo sigma. Na abstra??o, apenas a SEP obtida em M06-2X/aug-cc-pVDZ aponta para a forma??o de um intermedi?rio pr?-barreira. Coeficientes de velocidade foram determinados com base na Teoria do Estado de Transi??o Variacional, com aux?lio do programa kcvt. O coeficiente CCSD(T)/aug-cc-pVDZ//BHandHLYP/aug-cc-pVDZ para o mecanismo que inclui a participa??o do ?-PC ? de ???????=48,4?10?11 cm? molec-1 s-1, superestimado em rela??o ao coeficiente experimental em aproximadamente 4 vezes. Desvios dessa magnitude s?o esperados em c?lculos te?ricos, especialmente quando envolvem mol?culas volumosas. Pode-se constatar que a adi??o de OH deve ser a principal rota de degrada??o para o furano e seus derivados durante o dia. Al?m disso, foi poss?vel esclarecer o efeito da forma??o de intermedi?rios pr?-barreira nas rea??es entre DMF e o radical OH.

This thesis is dedicated to the theoretical study of the methyl cation CH3+ electronic states and, globally, falls within the study of the interstellar clouds molecular synthesis and the chemistry of the hydrocarbons which are present in high-energy plasmas such as in the experimental nuclear fusion reactor ITER. Among the different possible formation reactions, we chose two reactions involved in these fields: the ionization of the methyl radical CH3 ground state and the reactive collisions between simple carbonated or hydrocarbonated (C, CH+ and CH2+) and hydrogen species (H3+, H2 and H, respectively).<p><p>As this cation is characterized by 8 electrons and 4 nuclei, this allowed us to perform high-level ab initio calculations using the CASSCF/MRCI method with the Dunning aug-cc-p(C)VXZ basis sets. These calculations were completed by a study of different methodological effects such as the core-valence electronic correlation, the complete basis set extrapolation and the basis set superposition error.<p><p>We calculated equilibrium geometries (precision within 10^-5 angtröm and 10^-2° and their energies for the methyl radical and cation, studied the potential energy surfaces involved by the Jahn-Teller effect targeting the methyl cation E' states and achieved frequencies calculations. From these values were derived ionization potentials (IP) from the methyl radical ground state towards the methyl cation lowest-lying states (precision within 10^-2 eV). Vibrational corrections and nuclear relaxation effects were taken into account.<p><p>The calculated IPs and frequencies should facilitate the analysis of methyl radical threshold photoelectron spectra leading to the methyl cation lowest-lying states, recorded at the synchrotron facility Soleil by the Dr. Alcaraz group from the Université Paris-Sud.<p><p>Through reaction paths calculations using a quadratic steepest-descent method, we have proposed new reactional pathways enabling the connections between the different dissociation channels correlated to the cation lowest-lying triplet states. The absence of potential barriers in the energy profiles allows us to propose these reactions as sources, in interstellar clouds, of hydrocarbonated molecules whose stability increases with growing size according to the series C -> CH+ -> CH2+ -> CH3+.<p><p>The groups of Pr. Urbain from UCL and Dr. Savin from Columbia University studied the collisions in copropagating beams of C and H3+ leading to the formation of these hydrocarbonated species. The proposed reactional mechanisms are in good agreement with the experimental observations, what permits a better understanding of the chemistry behind these collisional processes of astrochemical interest. / Doctorat en Sciences / info:eu-repo/semantics/nonPublished

Abstract The thesis consists of seven studies dealing with high resolution vibration-rotation spectra of planar asymmetric tops. Six studies deal with D212CO and D213CO species of the formaldehyde molecule and one study is from DCOOH specie of the formic acid molecule. The measurements were carried out at high accuracy and the rotational analyses of the recorded spectra were performed. The observed anharmonic and Coriolis resonances were taking into account in the analyses. The rotational constants of the present and literature studies were used in evaluation of the planarity defects of formaldehyde and formic acid molecules in the summary part of the thesis. Finally, a semi-experimental structure for formaldehyde was obtained by employing experimental and theoretical data.

Le trioxyde de bore, B2O3, est l'archétype du système formateur de verre avec une unité structurale de base trigonale sous conditions ambiantes. Cette propriété confère à ce système un arrangement particulier à moyenne portée: les unités trigonales s'organisent en phase vitreuses en unités superstructurales appelées anneaux de boroxol. A l'aide de simulations de dynamique moléculaire incluant des potentiels polarisables paramétrés sur des simulations ab-initio, nous avons étudié les transformations structurales de B2O3 dans les phases vitreuse, liquide et cristalline. Nous avons suivi le changement de coordinence des atomes de bore sous une augmentation de pression et la disparition des anneaux, présents sous conditions ambiantes, sous haute pression et haute température. Les résultats obtenus par nos potentiels sont en bon accord avec des mesures expérimentales de diffraction de neutrons et de diffraction des rayons-X. Il font partis des meilleurs potentiels existant dans la littérature à ce jour pour décrire la structure de B2O3. / Boron trioxyde, B2O3, is the archetype of network-forming system with trigonal basic structural units under ambient conditions. In the glass under ambient conditions, it has been established that these triangles are packed in superstructural units called boroxol rings. Using molecular dynamics simulations including polarisable potentials we studied structural transformations of B2O3 in glassy, liquid and cristalline phases. We followed the boron coordination change as a function of pressure and the disapperance of boroxol rings at high pressure and high temperature. Results obtained using our potentials are in good agreement with experimental data: neutron diffraction and X-ray diffraction. They belong to best potentials in literature to describe correctly B2O3 structure.

Quantum Chemical Topology (QCT) descriptors, calculated from ab initio wave functions, have been utilised to model pKa and mutagenicity for data sets of pharmaceutically relevant compounds. The pKa of a compound is a pivotal property in both life science and chemistry since the propensity of a compound to donate or accept a proton is fundamental to understanding chemical and biological processes. The prediction of mutagenicity, specifically as determined by the Ames test, is important to aid medicinal chemists select compounds avoiding this potential pitfall in drug design. Carbocyclic and heterocyclic aromatic amines were chosen because this compounds class is synthetically very useful but also prone to positive outcomes in the battery of genotoxicity assays.The importance of pKa and genotoxic characteristics cannot be overestimated in drug design, where the multivariate optimisations of properties that influence the Absorption-Distribution-Metabolism-Excretion-Toxicity (ADMET) profiles now features very early on in the drug discovery process.Models were constructed using carboxylic acids in conjunction with the Quantum Topological Molecular Similarity (QTMS) method. The models produced Root Mean Square Error of Prediction (RMSEP) values of less than 0.5 pKa units and compared favourably to other pKa prediction methods. The ortho-substituted benzoic acids had the largest RMSEP which was significantly improved by splitting the compounds into high-correlation subsets. For these subsets, single-term equations containing one ab initio bond length were able to accurately predict pKa. The pKa prediction equations were extended to phenols and anilines.Quantitative Structure Activity Relationship (QSAR) models of acceptable quality were built based on literature data to predict the mutagenic potency (LogMP) of carbo- and heterocyclic aromatic amines using QTMS. However, these models failed to predict Ames test values for compounds screened at GSK. Contradictory internal and external data for several compounds motivated us to determine the fidelity of the Ames test for this compound class. The systematic investigation involved recrystallisation to purify compounds, analytical methods to measure the purity and finally comparative Ames testing. Unexpectedly, the Ames test results were very reproducible when 14 representative repurified molecules were tested as the freebase and the hydrochloride salt in two different solvents (water and DMSO). This work formed the basis for the analysis of Ames data at GSK and a systematic Ames testing programme for aromatic amines. So far, an unprecedentedly large list of 400 compounds has been made available to guide medicinal chemists. We constructed a model for the subset of 100 meta-/para-substituted anilines that could predict 70% of the Ames classifications. The experimental values of several of the model outliers appeared questionable after closer inspection and three of these have been retested so far. The retests lead to the reclassification of two of them and thereby to improved model accuracy of 78%. This demonstrates the power of the iterative process of model building, critical analysis of experimental data, retesting outliers and rebuilding the model.

Ce projet a pour but de répondre à quelques questions pendantes de planétologie en utilisant des méthodes de chimie quantique. Il recouvre principalement deux études.La première étude modélise les processus chimiques susceptibles d’expliquer la déplétion en gaz rares observée dans l’atmosphère de Titan par la mission Huygens ; l’étude considère la formation par association radiative, des complexes stables entre Ar, Kr, Xe et H3+ ou les ions protonés, ceci dans la nébuleuse proto-planétaire, avant la formation de Titan en tant qu’objet.La seconde étude analyse les mécanismes piégeant les volatiles dans les glaces, mécanismes à l’œuvre dans les comètes comme dans la lune Europe. Les scénarios d’une origine primordiale commune de O2 et S2 observés dans la comète 67P/C-G lors de la mission ROSETTA, ont pu être validés, donnant des rapports d’abondance avec l’eau proches des observations, et proposant une explication pour la corrélation/non corrélation avec l’eau pour les deux espèces. De même, un scénario pour l’origine des éléments mineurs Na et K détectés dans l’exosphère d’Europe, satellite pour lequel l’intérêt a ressurgi en raison des missions à venir, Juice de l’ESA et Europa Clipper de la NASA, a été étudié et s’est révélé valable également pour Mg et Ca pour lesquels des prédictions d’abondance ont été faites. Du point de vue des simulations numériques, ce travail combine deux approches ab-initio, une approche moléculaire pour la phase gazeuse du premier cas et une approche périodique du solide pour les autres cas. / This project aims at answering some questions in planetology by means of ab-inito quantum chemistry. It can be divided into two main studies. One models the chemical processes likely to explain the noble gases deficiency observed by the Huygens probe in the atmosphere of Titan; it investigates the formation of stable complexes between Ar, Kr, Xe and H3+ or protonated ions by radiative association, in the proto-solar nebula, prior to the formation of Titan. The other analyzes the trapping mechanisms of volatiles in the ice at work in comets as well as in Europa. Scenarios of primordial origin for O2 and S2, observed in comet 67P/C-G by the ROSETTA probe, were thus validated, giving abundance ratios with H2O close to those observed and proposing an explanation for the respective correlation/non-correlation with water of the two species. Also, a scenario for the origin of trace elements Na, K detected in the exosphere of Europa whose interest is revived by anticipating the missions Juice and Europa Clipper, was argumented and found available for Mg and Ca to predict relative abundancies to be observed. The computational work combines two ab-inito approaches, molecular calculations in gaseous phase in the first case and periodic solid state calculations in the second.

In this thesis we have investigated the correlated ground state properties of polymers by applying wave-function-based ab-initio quantum-chemical methods such as the Hartree-Fock approach, the full configuration interaction method (FCI), coupled-cluster (CC) and Moller-Plesset second-order perturbation (MP2) theory. The polymers we have studied are the boron-nitrogen polymers, i.e., polyiminoborane (PIB) and polyaminoborane (PAB), the lithium hydride chain and the beryllium hydride polymer as well as the polymethineimine (PMI). The optimized structural parameters, cohesive energies, polymerization ernergies, relative stabilities of isomeric forms and some band structure results are presented. The results demonstrated that quantum chemical ab initio methods can be applied successfully to infinite systems like polymers, although such calculations are still far from being routine.

Polyaromatic molecules functionalized with carboxylic groups have served as model systems for the growth of organic semiconducting films on a large variety of substrates. Most non-reactive substrates allow for a growth mode compatible with the bulk phase of the molecular crystal with two molecules in the unit cell, but some more reactive substrates including Ag(111) and Ag(110) can induce substantial changes in the first monolayer (ML). In the specific case of Ag(110), the adsorbate unit cell of both NTCDA and PTCDA resembles a brickwall structure, with a single molecule in the unit cell. From this finding, it can be concluded that the adsorbate-substrate interaction is stronger than typical inter-molecular binding energies in the respective bulk phases. In the present work, the interactions between small Ag(110) clusters and a single NTCDA or PTCDA molecule are investigated with different ab initio techniques. Four major ingredients contribute to the binding between adsorbate and substrate: Directional bonds between Ag atoms in the topmost layer and the oxygen atoms of the molecule, Pauli repulsion between filled orbitals of molecule and substrate, an attractive van-der-Waals interaction, and a negative net charge on the molecule inducing positive image charges in the substrate, resulting therefore in an attractive Coulomb interaction between these opposite charges. As both Hartree-Fock theory and density functional theory with typical gradient-corrected density functional do not contain any long range correlation energy required for dispersion interactions, we compare these approaches with the fastest numerical technique where the leading term of the van-der-Waals interaction is included, i.e. second order Møller-Plesset theory (MP2). Both Hartree-Fock and density functional theories result in bended optimized geometries where the adsorbate is interacting mainly via the oxygen atoms, with the core of the molecule repelled from the substrate. Only at the MP2 level, the inclusion of the major part of the attractive van-der-Waals interaction brings the adsorbate back to an arrangement close to parallel to the substrate, with very small differences in height between the different subunits. With respect to experimental data obtained on Ag(111), the calculated distance between adsorbate and substrate is somewhat smaller, indicating that the open Ag(110) surface interacts more strongly with the organic compounds. This is consistent with the fact that only Ag(110) induces a brickwall unit cell of the adsorbate, a clear sign for a particularly large adsorption energy. The resulting model geometries are analysed in terms of cohesive energy, Mulliken charges, core level shifts, and vibrational properties. / Polyaromatische Moleküle, die mit Carboxylgruppen funktionalisiert wurden, haben als Modellsysteme für das Wachstum von organischen Halbleiterfilmen für eine breite Palette von Substraten gedient. Für die meisten nichtreaktiven Substrate ist ein zum molekularen Kristall kompatibles Wachstum mit zwei Monolagen pro Einheitszelle möglich, jedoch erzeugen reaktivere Substrate wie z.B. Ag(111) oder Ag(110) bereits substanzielle Modifikationen in der ersten Monolage. Im speziellen Fall von Ag(110) bildet die Adsorbateinheitszelle sowohl von NTCDA als auch PTCDA eine sogenannte brickwall structure heraus mit einem einzigen Molekül pro Einheitszelle. Aus dieser Beobachtung kann geschlussfolgert werden, dass die Adsorbat-Substrat-Wechselwirkung stärker ist als die typischen intermolekularen Bindungsenergien in der entsprechenden Bulk-Phase. In der vorliegenden Arbeit werden die Wechselwirkungen zwischen kleinen Ag(110)-Clustern und einem einzelnen NCTDA oder PTCDA-Molekül mit verschiedenen ab initio-Techniken untersucht. Im Wesentlichen tragen vier Hauptbestandteile zur Bindung zwischen Adsorbat und Substrat bei: Gerichtete Bindungen zwischen Ag-Atomen in der obersten Substratschicht und den Sauerstoffatomen des Moleküls, Pauli-Abstoßung zwischen besetzten Orbitalen von Molekül und Substrat, eine anziehende Van-der-Waals-Wechselwirkung sowie einer negativen Ladung des Moleküls und der dazugehörigen positiven Spiegelladung im Substrat, die zu einer anziehenden Coulombwechselwirkung führen. Da weder die Hartree-Fock-Theorie noch die Dichtefunktionaltheorie mit dem typischen gradientenkorrigierten Dichtefunktional die für Dispersionswechselwirkungen benötigte langreichweitige Korrelationsenergie beinhalten, vergleichen wir diese beiden Ansätze mit der schnellsten numerischen Methode, die den dominierenden Term der Van-der-Waals-Wechselwirkung beinhaltet, nämlich der Møller-Plesset-Theorie zweiter Ordnung (MP2). Sowohl die Hartree-Fock-Theorie als auch die Dichtefunktionaltheorie sagen verbogene optimierte Geometrien voraus, die vorwiegend durch die Sauerstoffatome interagieren, wohingegen die zentralen Teile des Moleküls vom Substrat abgestoßen werden. Lediglich die MP2, die den wesentlichen Teil der anziehenden Van-der-Waals-Wechselwirkung beinhaltet, sagt eine beinahe parallele Anordnung des Moleküls an das Substrat voraus, wobei die einzelnen Untereinheiten des Moleküls nur unwesentlich verschiedene Abstände zum Substrat haben. Im Vergleich zu experimentellen Daten für Ag(111) ist die berechnete Distanz zwischen Adsorbat und Substrat etwas kleiner, woraus sich schlussfolgern lässt, dass die offene Ag(110)-Oberfläche stärker mit den organischen Verbindungen interagiert. Das ist im Einklang mit der Tatsache, dass nur Ag(110) die brickwall-Struktur des Adsorbats besitzt, was ein deutliches Zeichen für eine hohe Adsorptionsenergie ist. Die resultierenden Modellgeometrien wurden bezüglich ihrer Kohäsionsenergie, Mullikenladungen, Kernelektronenniveauverschiebungen und vibrationeller Eigenschaften untersucht.

Die überraschende Entdeckung von ferroelektrischem Hafniumoxid durch Böscke et al. im Jahre 2011 eröffnet zahlreich technologische Möglichkeiten wie zum Beispiel voll CMOS kompatible ferroelektrische RAM Speicherzellen. Als kristallographische Ursache für dieses Verhalten erwies sich die Raumgruppe Pca21. In theoretischen Untersuchungen mit Hilfe der Dichtefunktionaltheorie erwies sich diese Phase jedoch als thermodynamisch instabil. Ziel dieser Dissertation ist daher zu klären, wie diese Phase stabilisiert werden kann. Dazu werden Faktoren wie Stöchiometrie, Temperatur, Druck, Spannung, Grenzflächenenergie sowie Defekte und Dotierung mit Hilfe der Dichtefunktionaltheorie untersucht. Die errechneten Ergebnisse werden mit Hilfe von Modellen interpretiert, welche im laufe dieser Dissertation erarbeitet werden. Es zeigt sich, dass neben dem energetischen Zustand auch der Herstellungsprozess des Materials eine bedeutende Rolle in der Stabilisierung der ferroelektrischen Phase von Hafniumoxid spielt. Abschließend wird versucht Verbindung zum Experiment herzustellen, in dem experimentell zugängliche Stellschrauben aufgezeigt werden, welche die ferroelektrischen Eingenschaften von Hafniumoxid verbessern können und sich aus den erarbeiteten Ergebnissen ableiten. / The surprising discovery of ferroelectric hafnium oxide by Böscke et al. in 2011 enables various technological possibilities like CMOS compatible ferroelectric RAM devices. The space group Pca21 was identified as the crystallographic cause of this behavior. However, this phase was proved to be thermodynamically unstable by several theoretical studies using density functional theory. Therefore, the goal of this dissertation is to investigate physical effects contributing to the stabilization of the ferroelectric phase by means of density functional theory. These effects include stoichiometry, temperature, stress, strain, interface energy, as well as defects and dopants. The computational results will be interpreted with models, which will be developed within this dissertation. It will become apparent, that in addition to the energetic state, the production process of a sample plays an important role in the stabilization of the ferroelectric phase of hafnium oxide. In the conclusion, this work will attempt to find a connection to the experiment, by identifying experimentally accessible parameters within the computational results which can be used to optimize the ferroelectric properties of ferroelectric materials.