LCAO MO CALCULATIONS ON A SERIES OF NITRILES AND SOME RELATED MOLECULES BY A METHOD OF SELF-CONSISTENT FORMAL CHARGES

1964 ◽  
Vol 42 (6) ◽  
pp. 1323-1332 ◽  
Author(s):  
J. B. Moffat
Keyword(s):  
Experimental Data ◽  
Input Data ◽  
Electron Systems ◽  
Bond Orders ◽  
Mo Calculations ◽  
Bond Lengths ◽  
Triple Bonds ◽  
Self Consistent ◽  
Good Agreement ◽  
Lcao Mo

A method of self-consistent charges has been applied to an LCAO MO calculation of a series of nitriles and some related molecules. The π-electron bond orders and π-electron densities were calculated for all the molecules considered. The entire calculation was programmed for operation on the IBM 1620 with alterations of the input data for the different molecules. The calculated bond orders yield bond lengths for C—C and C=C bonds in good agreement with experimental data, except when two or more triple bonds are present in the molecule. By the assumption of additivity of the bond orders obtained for the two orthogonal pi-electron systems, bond orders are obtained which yield bond lengths in satisfactory agreement with the experimental results for all CC bonds. For the nitrile bonds the calculated bond orders were fitted to a linear equation with the experimental bond lengths.

N.M.R.-Studies of Bond Order in Azulene, Biphenylene and 1,6-Methano[10]annulene

1990 ◽  
Vol 43 (9) ◽  
pp. 1541 ◽  
Author(s):  
MJ Collins ◽  
S Sternhell ◽  
CW Tansey
Keyword(s):  
Experimental Data ◽  
Ground State ◽  
Bond Order ◽  
Membered Ring ◽  
Coupling Constants ◽  
Bond Orders ◽  
Bond Lengths ◽  
Theoretical Predictions ◽  
Electron Distributions ◽  
Good Agreement

The 4J(H-C-C-Me) coupling constants of methyl-substituted derivatives, probes of bond order, have been used to examine the ground-state π- electron distributions in azulene (1), biphenylene (2) and 1,6- methano [10] annulene (3). The experimental data obtained are in good agreement with theoretical predictions for biphenylene (2) and provide some evidence for π-electron disproportionation towards the five-membered ring in azulene (1). The bond orders in 1,6-methano [10] annulene (3) obtained in this work are at variance with those predicted on the grounds of bond lengths.

Analysis of Experimental Data From Ship Trajectories of Turning Circles in a Regular Seaway

2010 ◽  
Author(s):  
Joseph T. Klamo ◽  
Ray-Qing Lin
Keyword(s):  
Experimental Data ◽  
Quantitative Analysis ◽  
Time Varying ◽  
Ship Maneuvering ◽  
New Findings ◽  
Self Consistent ◽  
Calm Water ◽  
Experimental Laboratory ◽  
Ship Tracks ◽  
Good Agreement

The accurate prediction of the track of a ship maneuvering in a seaway is one of the most important tasks in seakeeping. Most ship maneuvering studies, both experimental and numerical, focus on maneuvering in calm water. Recently, Lin and Klamo (2010) used the Digital Self-consistent Ship Experimental Laboratory (DiSSEL) to study the ship track of a turning circle maneuver in a wave field. In that study, it was shown that their simulated ship trajectories had good agreement with experimentally measured tracks. This agreement motivated the following quantitative analysis of the experimental data to characterize the effects that wave impacts have on turning circle ship tracks. Our method involves describing the ship trajectories as sinusoids with time-varying means. We also estimate the uncertainty in the results from our analysis of the experimental measurements. The quantitative analysis shows overall agreement with Lin and Klamo (2010). New findings are also discussed such as changes in the distance and time to complete the maneuver as well as the speed and preferred directions of a drifting turning circle.

scholarly journals Bond lengths in naphthalene and anthracene

1951 ◽  
Vol 207 (1090) ◽  
pp. 306-320 ◽  
Keyword(s):  
Aromatic Hydrocarbon ◽  
Bond Length ◽  
Configuration Interaction ◽  
Bond Order ◽  
Bond Orders ◽  
Bond Lengths ◽  
Self Consistent ◽  
Hydrocarbon Molecules ◽  
Experimental Values ◽  
Correction Terms

An extremely careful inquiry is made into the possibility of predicting bond lengths in condensed aromatic hydrocarbon molecules. Agreement with the best experimental values, such as those of Robertson, Abrahams, White, Mathieson and Sinclair, is fairly easily obtained to an accuracy of about 0.02Å. This shows that the concept of fractional bond order may quite properly be used to infer bond lengths. Both the molecular-orbital and resonance methods are equally good for this purpose. Predictions to within less than 0.02Å require the introduction of new factors usually neglected. No less than five such factors are discussed: ( а ) electrostatic forces, arising from possible differences in electronegativity of the various carbon atoms, ( b ) changes of bond orders due to electronegativity differences, ( c ) variation of resonance integrals with bond length, ( d ) obtaining a self-consistent set of resonance integrals, ( e ) inclusion of configuration interaction. Correction terms which result from these improvements lie between 0 and 0.015Å, and are not all of the same sign. It is unlikely therefore that this type of analysis will be able to give confident predictions of bond lengths to less than 0.01Å.

The energy of a unitary Fermi gas in the normal phase including the effect of induced interaction

2015 ◽  
Vol 29 (32) ◽  
pp. 1550207 ◽  
Author(s):  
Hao Gong ◽  
Xiao-Xia Ruan ◽  
Hou-Rong Pang ◽  
Hong-Shi Zong
Keyword(s):  
Experimental Data ◽  
Chemical Potential ◽  
Normal Phase ◽  
Fermi Gases ◽  
Matrix Approximation ◽  
Ultracold Fermi Gases ◽  
Self Consistent ◽  
Unitary Fermi Gas ◽  
T Matrix ◽  
Good Agreement

In this paper, taking into account the effect of the induced interaction, we calculate the energy of ultracold Fermi gases at unitarity in the framework of non-self-consistent T-matrix approximation (nTMA) above the critical temperature and compare the result with the experimental data and other theoretical calculation without induced interaction. Our calculated chemical potential is higher than the experimental data, but our calculated energy obtains a good agreement with Tokyo experiment for temperature range between [Formula: see text] and [Formula: see text].

Application of Visco-Plastic Self Consistent Approach to Model Deformation Characteristics of Magnesium with Different Textures

2011 ◽  
Vol 702-703 ◽  
pp. 80-84
Author(s):  
Apu Sarkar ◽  
J.K. Chakravartty
Keyword(s):  
Experimental Data ◽  
Experimental Evidence ◽  
Uniaxial Tensile ◽  
Deformation Characteristics ◽  
Self Consistent ◽  
Plastic Forming ◽  
Constitutive Response ◽  
Low Symmetry ◽  
Consistent Approach ◽  
Good Agreement

The viscoplastic self-consistent (VPSC) formulation is by now a well established approach for simulating texture development and constitutive response during plastic forming of high and low-symmetry polycrystals. In this work we have used the VPSC approach to model the uniaxial tensile and compressive deformation characteristics of pure magnesium with random and extruded texture. We compare our results with experimental data and find that they are in good agreement with the available experimental evidence.

Interpretation of Microstructure of Poly-Isoprene and Polybutadiene Obtained in Anionic Polymerization

1967 ◽  
Vol 40 (3) ◽  
pp. 883-894 ◽  
Author(s):  
K. F. O'Driscoll ◽  
T. Yonezawa ◽  
T. Higashimura
Keyword(s):  
Experimental Data ◽  
Anionic Polymerization ◽  
Quantitative Model ◽  
Relative Reactivity ◽  
Mo Calculations ◽  
Model Based ◽  
Polymer Microstructures ◽  
Lcao Mo

Abstract A mechanism is proposed for the anionic homopolymerization of the diene monomers isoprene and butadiene. This mechanism qualitatively explains how the various polymer microstructures occur. A quantitative model based on this mechanism is treated by LCAO-MO calculations which include the effect of the counterion on the propagating chain. The results of the calculations are then compared with experimental data on microstructure and relative reactivity in hydrocarbon and tetrahydrofuran solvents. In every instance the comparisons give correct, semiquantitative agreement between calculation and experiment.

Ground states of conjugated molecules. XVII. The l.c.a.o. s.c.f. m.o. treatment of compounds containing nitrogen and oxygen

1970 ◽  
Vol 315 (1523) ◽  
pp. 457-464 ◽  
Keyword(s):  
Experimental Data ◽  
Ground State ◽  
Ground States ◽  
Resonance Integral ◽  
Conjugated Molecules ◽  
Bond Lengths ◽  
Conjugated Hydrocarbons ◽  
Good Account ◽  
The One ◽  
Good Agreement

In a recent paper (Dewar & Harget 1970) we described an l.c.a.o. s.c.f. m.o. treatment which gave an extremely good account of the ground-state properties of conjugated hydrocarbons. This treatment differed from the previous procedure used in this department, in that the one-electron core resonance integral B is evaluated using theMulliken approximation, B = KS . We now describe an extension of this treatment to conjugated molecules containing nitrogen or oxygen. Calculated heats of atomization and bond lengths are given for some nitrogen and oxygen compounds, and are in good agreement with experimental data.

A Self-Consistent Scheme for the Relaxation Behavior of Metals

1981 ◽  
Vol 48 (4) ◽  
pp. 779-784 ◽  
Author(s):  
G. J. Weng
Keyword(s):  
Experimental Data ◽  
Relaxation Behavior ◽  
The Self ◽  
Combined Stress ◽  
Temperature Dependent ◽  
Free Process ◽  
Self Consistent ◽  
Temperature Environment ◽  
Stress Variations ◽  
Good Agreement

We identify in this paper that stress relaxation in metals is a “strain-free” process. The corresponding self-consistent relations between the strain, and stress variations of a grain and of its aggregate are derived from Eshelby’s solution of an ellipsoidal inclusion. It is shown that, under such a process, the strain in a more favorably oriented grain continues to rise and that its stress decreases more drastically than that of the aggregate; conversely, for a less favorably oriented grain, its strain decreases and its stress relaxes less. The self-consistent relations are supplemented with a temperature-dependent, physically consistent constitutive equation for the slip system. Such an equation enables us to determine the single crystal constants at one temperature from the polycrystal data at another temperature; it also makes the self-consistent scheme applicable to the varying-temperature environment. The established theory was finally applied to predict the relaxation behavior of an RR-59 aluminum alloy under combined stress; the results showed reasonably good agreement with the experimental data.

The pressure and entropy of a unitary Fermi gas with particle-hole fluctuation

2018 ◽  
Vol 32 (01) ◽  
pp. 1750364
Author(s):  
Hao Gong ◽  
Xiao-Xia Ruan ◽  
Hong-Shi Zong
Keyword(s):  
Experimental Data ◽  
Fermi Gas ◽  
Experimental Measurements ◽  
Matrix Approximation ◽  
Self Consistent ◽  
Unitary Fermi Gas ◽  
T Matrix ◽  
Theoretical Results ◽  
Previous Prediction ◽  
Good Agreement

We calculate the pressure and entropy of a unitary Fermi gas based on universal relations combined with our previous prediction of energy which was calculated within the framework of the non-self-consistent T-matrix approximation with particle-hole fluctuation. The resulting entropy and pressure are compared with the experimental data and the theoretical results without induced interaction. For entropy, we find good agreement between our results with particle-hole fluctuation and the experimental measurements reported by ENS group and MIT experiment. For pressure, our results suffer from a systematic upshift compared to MIT data.

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