AbinitioSCF and CI studies on the ground state of the water molecule. I. Comparison of CGTO and STO basis sets near the Hartree–Fock limit

1975 ◽  
Vol 63 (5) ◽  
pp. 2162-2174 ◽  
Author(s):  
Bruce J. Rosenberg ◽  
Isaiah Shavitt
Keyword(s):  
Water Molecule ◽  
Ground State ◽  
Basis Sets ◽  
Hartree Fock

Gaussian basis sets for the atoms from K through Xe

2001 ◽  
Vol 79 (2) ◽  
pp. 121-123 ◽  
Author(s):  
R Centoducatte ◽  
E VR de Castro ◽  
F E Jorge
Keyword(s):  
Key Words ◽  
Ground State ◽  
Basis Sets ◽  
Gaussian Basis Sets ◽  
Hartree Fock ◽  
Generator Coordinate ◽  
Discretization Technique ◽  
Total Energies

An improved generator coordinate Hartree-Fock (IGCHF) method is used to generate Gaussian basis sets for the atoms from K (Z = 19) through Xe (Z = 54). The Griffin-Hill-Wheeler-HF equations are integrated using the integral discretization technique. The ground state HF total energies obtained by us are compared with those calculated with the original GCHF method and with other approaches reported in the literature. The largest difference between our energy values and the corresponding ones computed with a numerical HF method is equal to 6.003 mhartree for Kr (Z = 36).Key words: improved generator coordinate Hartree-Fock method, Gaussian basis sets, total energies.

Theoretical studies on the absorption and luminescent properties of a series of derivatives of 1,3-diphenyl-5-pyrene-2-yl-4,5-dihydro-1H-pyrazole

2005 ◽  
Vol 83 (2) ◽  
pp. 166-173 ◽  
Author(s):  
Xiao-Juan Liu ◽  
Ji-Kang Feng ◽  
Ai-Min Ren ◽  
Xin Zhou ◽  
Hong Cheng
Keyword(s):  
Ground State ◽  
Emission Spectra ◽  
Luminescent Properties ◽  
Basis Set ◽  
Basis Sets ◽  
Absorption And Emission ◽  
Reaction Field ◽  
Hartree Fock ◽  
Polarized Continuum Model ◽  
Experimental Values

The absorption and emission spectra for a series of substituted 1,3-diphenyl-5-pyrene-2-yl-4,5-dihydro-1H-pyrazole (DPPyP) molecules are computed by TDDFT methods. The solvent effect is modeled using the self-consistent reaction field (SCRF) method with Tomasi's polarized continuum model (PCM). The ground-state geometries were optimized by the Hartree–Fock method with the 6-31G basis set (and also with 3-21G* for molecule A) (HF/6-31G), and the lowest singlet excited-state geometries were optimized at the ab initio CIS level with the 6-31G basis set (CIS/6-31G). The calculated results indicate that the TDDFT method can reproduce the experimental values. We consider the effects of different basis sets on the optimization of the ground-state geometries. Specially, some insights on the differences observed for these compounds in changing the substituted donors (H, CH3, and NH2) and acceptor group (CN) are given; the results indicate that introduction of the donor groups will lead emission to be red-shifted, while introduction of the acceptor will induce the emission to be blue-shifted, which provides useful information for modulating light-emitting material colors.Key words: absorption and emission, TDDFT, CIS, SCRF–PCM.

scholarly journals AB INITIO STUDY ON OPTIMIZATION OF BISPHENOL A AND PHOSGENE TO MANUFACTURE POLYCARBONATE

2020 ◽  
Vol 20 (4) ◽  
pp. 995-998
Author(s):  
BAHTIYAR A. MAMEDOV ◽  
ELIF SOMUNCU ◽  
EBRU KARATAS
Keyword(s):  
Experimental Data ◽  
Bisphenol A ◽  
Ab Initio ◽  
Ground State ◽  
Optimization Method ◽  
Geometric Optimization ◽  
Basis Sets ◽  
Ab Initio Study ◽  
Hartree Fock ◽  
Design Materials

Geometric optimization is played an important to manufacture and design materials in many implementations. Therefore the choice of optimization method is of considerable significance to easily solve the problems. In this work, the ground state geometries for bisphenol A and phosgene that manufacture polycarbonate have been optimized using the Hartree-Fock method with different basis sets. The optimization results for bisphenol A and phosgene are compared with theoretical and experimental data. The obtained optimizations results have been shown that our data are in agreement with the literature and experimental data.

Simplified Non-Empirical Unrestricted Hartree-Fock Approximation (SUHF) for the Calculation of Electronic Ground State Properties of Molecules with Closed and Open Valence Shells. II. Diatomic Molecules

1993 ◽  
Vol 48 (7) ◽  
pp. 834-840
Author(s):  
Wolfhard Koch ◽  
Klaus Neymeyr ◽  
Markus Pernpointner ◽  
Barbara Schaper ◽  
Klaus Strecker
Keyword(s):  
Ground State ◽  
Diatomic Molecules ◽  
Electronic Ground State ◽  
Basis Sets ◽  
Gaussian Basis Sets ◽  
Atomic Spin ◽  
Hartree Fock ◽  
Total Energies ◽  
Simplified Procedure ◽  
Electronic Ground

Abstract A comparison of numerical Simplified Unrestricted Hartree-Fock (SUHF) results (electronic ground state configurations, total energies, first ionization potentials, atomic charges, atomic spin densities of diatomic molecules) with those of equivalent standard calculations suggests the applicability of the non-empirical but drastically simplified procedure. SUHF may even approach ab initio quality obtained with simple (STO-3G) contracted Gaussian basis sets.

Correlation in the Ground State of He Atom

1981 ◽  
Vol 36 (3) ◽  
pp. 272-275 ◽  
Author(s):  
Subal Chandra Saha ◽  
Sankar Sengupta
Keyword(s):  
Ground State ◽  
Zero Order ◽  
Consistent Variation ◽  
Hartree Fock ◽  
Perturbation Procedure ◽  
Self Consistent ◽  
He Atom ◽  
Atomic Parameters

It is possible to reproduce the entire results of Pekeris et al. of different atomic parameters for the He atom by introducing (ll) type correlation in a self consistent variation perturbation procedure using the Hartree-Fock (HF) wavefunction as the zero-order wavefunction

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