Molecular Screening in Helium Molecular Ion

1971 ◽  
Vol 49 (20) ◽  
pp. 3406-3408 ◽  
Author(s):  
C. M. Wang ◽  
B. Musulin
Keyword(s):  
Quantum Chemical Calculations ◽  
Quantum Chemical ◽  
Empirical Method ◽  
Molecular Screening ◽  
Energy Calculations ◽  
Molecular Ion ◽  
Semi Empirical ◽  
Orbital Exponents

Variational energy calculations for He2+ were performed and the results were used to evaluate a semi-empirical method for choosing orbital exponents in quantum chemical calculations.

scholarly journals Conformation analysis of three germacranolides by the PM3 semi-empirical method

2003 ◽  
Vol 68 (4-5) ◽  
pp. 281-289 ◽  
Author(s):  
Slobodan Milosavljevic ◽  
Ivan Juranic ◽  
Ivana Aljancic ◽  
Vlatka Vajs ◽  
Nina Todorovic
Keyword(s):  
Low Temperature ◽  
Quantum Chemical Calculations ◽  
1H Nmr ◽  
Quantum Chemical ◽  
Nmr Spectra ◽  
Sesquiterpene Lactones ◽  
Empirical Method ◽  
Conformation Analysis ◽  
Karplus Equation ◽  
Semi Empirical

The conformations of the C-6 lactonized germacranolides 1?3 were calculated by applying the PM3 semi-empirical method. The low-temperature 1H-NMR spectra of parthenolide (1) were also measured. The relations between the calculated and the experimentally determined geometries were established using a modified Karplus equation. The applied quantum-chemical calculations proved to be an efficient and easy-to-use tool for the elucidation and prediction of the properties of germacranolide-type sesquiterpene lactones.

scholarly journals THEORETICAL STUDY OF NUCLEOSIDE5´-PHOSPHORAZOLIDE-2´,3´-CYCLO(THIO)CARBONATE FORMATION POSSIBILITY IN REACTION OF NUCLEOTIDES AND N,N´-ACYLBISAZOLES BY QUANTUM-CHEMICAL METHODS

2017 ◽  
Vol 20 (3) ◽  
pp. 148-153
Author(s):  
I.V. Lazareva ◽  
Z.P. Belousova ◽  
Yu.P. Zarubin ◽  
P.P. Purygin
Keyword(s):  
Quantum Chemical ◽  
Theoretical Study ◽  
Empirical Method ◽  
Chemical Methods ◽  
Carbonate Formation ◽  
Quantum Chemical Methods ◽  
Semi Empirical ◽  
Imidazole Fragment

Nucleoside-5´-phosphates and N,N´-(thio)carbonylbisazoles interaction was studied for the evaluation of nucleoside-5´-phosphorazolide-2´,3´cyclo(thio)carbonate formation possibility by the semi-empirical method PM6 of SCIGRESS Modeling 3.0.0 software. Azole moiety involves imidazole fragment. It was shown that formation of nucleoside-5´-phosphorazolide2´,3´-cyclo(thio)carbonates is energetically less efficient than formation of nucleotide-5´-phosphorazolides.

scholarly journals Crystal Structure and Semi-Empirical Quantum Chemical Calculations Related to the Stability of N,N' - (2'- furfurylidene)bis(morpholine)

1998 ◽  
Vol 9 (1) ◽  
pp. 47-50
Author(s):  
Norberto Pelentir ◽  
Obdulio G. Miguel ◽  
Ines M.C. Brighente ◽  
Santiago F. Yunes ◽  
Ivo Vencato ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Quantum Chemical Calculations ◽  
Quantum Chemical ◽  
The Stability ◽  
Semi Empirical

scholarly journals Theoretical Simulation of the Zeke Spectra of Naphthalene From Single Vibronic Levels of S1

1999 ◽  
Vol 19 (1-4) ◽  
pp. 105-108 ◽  
Author(s):  
Fabrizia Negri ◽  
Marek Z. Zgierski
Keyword(s):  
Ab Initio ◽  
Quantum Chemical Calculations ◽  
Ground State ◽  
Quantum Chemical ◽  
Electronic States ◽  
Perturbative Expansion ◽  
Molecular Structures ◽  
Theoretical Simulation ◽  
Vibronic States ◽  
Semi Empirical

We present the simulations and analysis of the two-color ZEKE spectra of naphthalene, performed with the help of quantum chemical calculations of molecular parameters followed by the modelling of vibronic intensities. Ab initio and semi-empirical calculations were carried out to obtain molecular structures of neutral and ionic naphthalene, and vibronic perturbations that couple the electronic states. It is shown that the intensities, simulated with a model based on the perturbative expansion of vibronic states, nicely reproduce the observed spectra and contribute to reassign some of the ground state frequencies of naphthalene cation.

Spectrum of copper phthalocyanine: Experiments and semi-empirical quantum chemical calculations

2008 ◽  
Vol 403 (10-11) ◽  
pp. 1704-1707 ◽  
Author(s):  
Fang Li ◽  
Qiguang Zheng ◽  
Guang Yang ◽  
Nengli Dai ◽  
Peixiang Lu
Keyword(s):  
Quantum Chemical Calculations ◽  
Quantum Chemical ◽  
Copper Phthalocyanine ◽  
Semi Empirical
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