Optimal basis sets for deep levels. II. Defect-molecule approximation

1985 ◽  
Vol 32 (4) ◽  
pp. 2260-2265
Author(s):  
E. O. Kane
Keyword(s):  
Deep Levels ◽  
Basis Sets ◽  
Optimal Basis

Optimal basis sets for CBS extrapolation of the correlation energy: oVxZ and oV(x+d)Z

2019 ◽  
Vol 150 (15) ◽  
pp. 154106 ◽  
Author(s):  
A. J. C. Varandas ◽  
F. N. N. Pansini
Keyword(s):  
Correlation Energy ◽  
Basis Sets ◽  
Optimal Basis

Optimal basis sets for detailed Brillouin-zone integrations

1996 ◽  
Vol 54 (23) ◽  
pp. 16464-16469 ◽  
Author(s):  
Eric L. Shirley
Keyword(s):  
Brillouin Zone ◽  
Basis Sets ◽  
Optimal Basis

Construction of Optimal Basis Sets in Approximate Theories of the Electronic Structure of Molecules

1981 ◽  
Vol 36 (4) ◽  
pp. 373-377
Author(s):  
Z. B. Maksić
Keyword(s):  
Electronic Structure ◽  
Basis Functions ◽  
Basis Sets ◽  
Optimal Basis ◽  
Structure Of Molecules ◽  
Löwdin Orthogonalization ◽  
Orthogonalization Procedure

Properties of the weighted Löwdin orthogonalization procedure are thoroughly discussed. It is shown that its flexibility might be very useful in the construction of optimal truncated basis sets in approximate theories of the electronic structure of molecules and solids. The relevance of pairwise nonorthogonal (hybrid) basis functions is pointed out

A real-time method to reduce ballistocardiogram artifacts from EEG during fMRI based on optimal basis sets (OBS)

2016 ◽  
Vol 127 ◽  
pp. 114-125 ◽  
Author(s):  
Xia Wu ◽  
Tong Wu ◽  
Zhichao Zhan ◽  
Li Yao ◽  
Xiaotong Wen
Keyword(s):  
Real Time ◽  
Basis Sets ◽  
Optimal Basis

scholarly journals Basis Set Selection for Calculation of Structural and Electronic Properties of Systems Incorporating a Superoxide Radical in an Aqueous Medium

2021 ◽  
pp. 53-57
Author(s):  
A.V. Ryabykh ◽  
M.A. Pirogov ◽  
O.A. Maslova ◽  
S.A. Beznosyuk
Keyword(s):  
Aqueous Medium ◽  
Superoxide Radical ◽  
Selection Criterion ◽  
Polarizable Continuum Model ◽  
Basis Set ◽  
Basis Sets ◽  
Optimal Basis ◽  
Molecular Systems ◽  
Structural And Electronic Properties ◽  
Computer Calculations

In this work, computer simulation has been carried out, and the molecular parameters of oxygen and a superoxide ion have been calculated to select the most optimal basis set of functions for further quantum mechanical calculations that include the presence of reactive oxygen species. For each particle, the equilibrium bond lengths and averaged polarizabilities in a continuous dielectric aqueous medium are obtained with the Conductor-like Polarizable Continuum Model (CPCM) and Solvation Model based on Density (SMD). Calculations for the 16 basic sets are conducted using the Orca software package. The obtained numerical values are compared with experimental data. The electron affinity energy of the oxygen molecule is used as the main selection criterion. The total time of computer calculations for each basis set is considered, and the most optimal basis sets are selected. The basis sets 6-31+G(d), 6-311+G, def2-TZVPD, and aug-cc-pVDZ are recommended for numerical calculations of molecular systems incorporating molecular oxygen and superoxide radical as its reduction product.

Removal of FMRI environment artifacts from EEG data using optimal basis sets

NeuroImage ◽  
2005 ◽  
Vol 28 (3) ◽  
pp. 720-737 ◽  
Author(s):  
R.K. Niazy ◽  
C.F. Beckmann ◽  
G.D. Iannetti ◽  
J.M. Brady ◽  
S.M. Smith
Keyword(s):  
Basis Sets ◽  
Optimal Basis ◽  
Eeg Data

Experimental and Theoretical (ab initio and DFT) Analysis of UV-Vis Spectra, Thermodynamic Functions and Non-linear Optical Properties of 2-Chloro-3,4-Dimethoxybenzaldehyde

2015 ◽  
Vol 8 (2) ◽  
pp. 2122-2134
Author(s):  
Sarvendra Kumar ◽  
Rajesh Kumar ◽  
Jayant Teotia ◽  
M. K. Yadav
Keyword(s):  
Thermodynamic Functions ◽  
Title Compound ◽  
Density Functional ◽  
Structural Characteristics ◽  
Basis Sets ◽  
Ultraviolet Absorption Spectrum ◽  
Non Linear ◽  
Different Temperatures ◽  
Linear Optical Properties ◽  
Linear Optical

In the present work, UV- Visible spectra of 2-Chloro-3,4-Dimethoxybenzaldehyde (2,3,4-CDMB) compound  have been carried out experimentally and theoretically. The ultraviolet absorption spectrum of title compound in three solvents (Acetone, Diethyl Ether, CCl4) of different polarity were examined in the range of 200–500 nm. The structure of the molecule was optimized and the structural characteristics were determined by HF and DFT (B3LYP) methods with 6-31+G(d,p) and 6-311++G(d,p) as basis sets. The excitation energy, wavelength corresponds to absorption maxima () and oscillator strength (f) are calculated by Time-Dependent Density Functional Theory (TD-DFT) using B3LYP/6-31+G(d,p) and B3LYP/6-311++G(d,p) as basis sets. The electric dipole moment (μ), polarizability (α) and the first hyperpolarizability (β ) have been computed to evaluate the non-linear optical (NLO) response of the investigated compound by HF and DFT (B3LYP) with already mentioned basis sets. Thermodynamic functions of the title compound at different temperatures were also calculated.

Electronic Structure Benchmark Calculations of Inorganic and Biochemical Carboxylation Reactions

2018 ◽  
Author(s):  
Oscar A. Douglas-Gallardo ◽  
David A. Sáez ◽  
Stefan Vogt-Geisse ◽  
Esteban Vöhringer-Martinez
Keyword(s):  
Electronic Structure ◽  
Chemical Reactions ◽  
Density Functional ◽  
Correlation Energy ◽  
Electronic Energy ◽  
Basis Sets ◽  
Electronic Correlation ◽  
Correct Description ◽  
Carbon Dioxide Co2 ◽  
High Level

<div><div><div><p>Carboxylation reactions represent a very special class of chemical reactions that is characterized by the presence of a carbon dioxide (CO2) molecule as reactive species within its global chemical equation. These reactions work as fundamental gear to accomplish the CO2 fixation and thus to build up more complex molecules through different technological and biochemical processes. In this context, a correct description of the CO2 electronic structure turns out to be crucial to study the chemical and electronic properties associated with this kind of reactions. Here, a sys- tematic study of CO2 electronic structure and its contribution to different carboxylation reaction electronic energies has been carried out by means of several high-level ab-initio post-Hartree Fock (post-HF) and Density Functional Theory (DFT) calculations for a set of biochemistry and inorganic systems. We have found that for a correct description of the CO2 electronic correlation energy it is necessary to include post-CCSD(T) contributions (beyond the gold standard). These high-order excitations are required to properly describe the interactions of the four π-electrons as- sociated with the two degenerated π-molecular orbitals of the CO2 molecule. Likewise, our results show that in some reactions it is possible to obtain accurate reaction electronic energy values with computationally less demanding methods when the error in the electronic correlation energy com- pensates between reactants and products. Furthermore, the provided post-HF reference values allowed to validate different DFT exchange-correlation functionals combined with different basis sets for chemical reactions that are relevant in biochemical CO2 fixing enzymes.</p></div></div></div>

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