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Showing 1 to 20 of 131 for “"basis set"”.
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Product Basis Set Variational Calculations of Triatomic Rovibrational Energy Levels and Wavefunctions
If both the potential energy surface of a molecule and trial functions for a variational calculation are expanded in products of internal coordinate functions, the Hamiltonian matrix may be speedily built because all required integrals are one-dimensional. New methods, especially for calculating …
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Introduction of a Fully Relativistic Capable Basis Set in the ab initio Orthogonalized Linear Combination of Atomic Orbitals Method
… YBCO, SnO2 and BiF3. The improvements to the basis set reflect an improvement in both computational speed and accuracy
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Exploration of basis set issues for calculation of intermolecular interactions and density functional theory calculations of vanadium oxide clusters and their reactions with sulfur dioxide
… of intermolecular interactions requires a large basis set in order to describe systems with dominant dispersion interaction accurately. This work focuses on calculation of intermolecular bonding energies of weakly bound systems within the supermolecular method and on issues related to the choice …
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The performance of density functional theory with the correlation consistent basis sets.
… consistent and polarization consistent basis sets to investigate the structures and energetics for a series of first-row closed shell and several second-row molecules of potential importance in atmospheric chemistry. The impact of basis set choice upon molecular description has been …
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The development of a local orbital method and its applications to aluminum and platinum clusters
… d orbitals into the original local orbital basis set of $sp\sp3$ orbitals. This enables the treatment of most elements in the periodic table including all $sp\sp3$ bonding elements and almost all transition metals with $sp\sp3d\sp5$ bondings. The task was a major modification (13,000 new …
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Explicitly correlated Green's function methods for calculating electron binding energies
… the Fock subspace in a finite single-particle basis. However, these methods suffer from slow asymptotic decay of basis set incompleteness error. An energy-dependent explicitly correlated (F12) formalism for Green's function is presented that achieves faster convergence to the basis set limit. …
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Density-functional Theory Applied To Problems In Catalysis And Electrochemistry
… of water depends strongly on the particular basis set used. Applying a systematic approach to varying the basis set, we find that the basis set which results in good agreement with experimental binding energies for isolated water dimers also provides a reasonable description of the radial …
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Accurate Calculations of Molecular Properties with Explicitly Correlated Methods
… Explicitly correlated methods overcome this basis set problem by including the inter-electronic distances (rij) explicitly in wave function expansions. Here, the origin of the basis set problem of conventional wave function methods is reviewed, and a short history of explicitly correlated …
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Electronic structure and transport in molecular and nanoscale electronics
… Green's function method, we develop a minimal basis-set of quasiatomic orbitals from plane-wave density functional theory (DFT) results. This minimal basis-set resembles quasi-angular momentum characteristics in solid state systems and it further validates Slater's original idea of linear …
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Development of Property Prediction Methods for Sodium-ion Battery Electrolytes
… carbonate (EC). A larger B3LYP/6-311++G** basis set was used to optimize the geometry and compute the vibrational spectrum of a single molecule EC and its complex including the sodium cation as a benchmark. Both the efficiency and accuracy of ab initio calculations were taken into account …
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Performance analysis of functional expansion tallies on 2D PWR pin cell
… an arbitrary series of independent functions as basis set is then proposed and tested. To capture the self-shielding effect of the U-238 absorption rate, an exponential basis set is chosen. The results show that the exponential basis set can reduce the optimum order of expansion by half comparing …
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Accurate Quantum Mechanical Calculations of Hf-Hf Scattering Cross Sections
A set of time-independent scattering calculations were performed on a system of two hydrogen flouride molecules. The log-derivative method was used in an attempt to calculate fully converged integral and differential cross sections for rotationally inelastic scattering with a high degree of …
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Development of more accurate computational methods within linear-scaling density functional theory
… developed with parameters optimised for a large set of dispersion bound complexes for the onetep code. This provides a much improved description of dispersion forces which are especially important for biological systems. There is a hierarchy of exchange-correlation functionals available the most …
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A Computational Study on 18+δ Organometallics
… effective core potential and associated basis set was used for metals (Co/Re) and the 6-31G* basis set was used for all other elements. The differences of bond angles, bond distances, natural atomic charges and IR vibrational frequencies were compared with the available experimental …
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Characterization of intermolecular pi-Type interactions using sophisticated quantum mechanical, electronic structure computations
… main components of computational chemistry, the basis set and method, determines the ``cost'' (disk, memory, and CPU time) of a computation. A variety of basis sets and methods have been developed in the past century. The focus of this report is to accurately describe non-covalent interactions …
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Construction and Application of Reference Scales for the Characterization of Cationic Electrophiles and Neutral Nucleophiles
A basis-set of reference electrophiles (benzhydrylium ions) and reference nucleophiles (pi-systems) has been constructed on the basis of the equation log k = s(E+N), which covers reactivity ranges of several orders of magnitude. The reference compounds of this basis-set proved to be very useful for …
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Machine-Learned Representations of Basis Sets and Their Application in Quantum Computational Chemistry
… Hilbert space via compact and efficient basis sets. However, most optimized basis sets either rely on predefined heuristics or require expensive classical computations, such as CASSCF orbital optimization or ℓ1-norm minimization of the Hamiltonian. In this work, we introduce a general …
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Exploration and Optimization of the One- and Many-particle Basis Sets in Modern Explicitly Correlated Electronic Structure
Basis set incompleteness error (BSIE) remains one of the largest sources of error in modern electronic structure calculations. Despite the many development producing methods that circumvent the issue by using grids or real-space methods, the linear combination of atomic orbitals (LCAO) approach …
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Autonomous altitude estimation of a miniature helicopter using a single onboard camera.
… altitude value. We learn an over complete sparse basis set from a corpus of unlabeled images capturing the texture variations. This is followed by regression of this basis set against a training set of altitudes. Finally, a spatio-temporal Markov Random Field is modeled over the altitudes in test …
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Hybrid density functionals with proper exact exchange
… thisimprovement increases with the size of the basis set and the size of the system. The max-imum improvement in standard enthalpies of formation of the G3-3 test set is 0.4 kcal/molwhen using 6-311++G(3df,3pd) basis set. For a hybrid density functional, the difference in theground-state …
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