Probing solvent effect and strong and weak interactions in 2-Nitrophenyl-hydrazine using independent gradient model and Hirshfeld from wave function calculation

2021 ◽  
Vol 341 ◽  
pp. 117345
Author(s):  
S. Sarala ◽  
S.K. Geetha ◽  
S. Muthu ◽  
Ahmad Irfan
Keyword(s):  
Wave Function ◽  
Solvent Effect ◽  
Weak Interactions ◽  
Gradient Model ◽  
Function Calculation

scholarly journals The Independent Gradient Model: A New Approach for Probing Strong and Weak Interactions in Molecules from Wave Function Calculations

ChemPhysChem ◽  
2018 ◽  
Vol 19 (6) ◽  
pp. 724-735 ◽  
Author(s):  
Corentin Lefebvre ◽  
Hassan Khartabil ◽  
Jean-Charles Boisson ◽  
Julia Contreras-García ◽  
Jean-Philip Piquemal ◽  
...  
Keyword(s):  
Wave Function ◽  
Weak Interactions ◽  
New Approach ◽  
Gradient Model

THE SUPERFLUID PHASES OF LIQUID 3He: BCS THEORY

2010 ◽  
Vol 24 (25) ◽  
pp. 2525-2539 ◽  
Author(s):  
A. J. LEGGETT
Keyword(s):  
Magnetic Field ◽  
Wave Function ◽  
Weak Interactions ◽  
Spin Fluctuation ◽  
Zero Magnetic Field ◽  
Bcs Theory ◽  
Neutral System ◽  
Cooper Pairing ◽  
Pair Wave Function

Following the success of the original BCS theory as applied to superconductivity in metals, it was suggested that the phenomenon of Cooper pairing might also occur in liquid 3- He , though unlike the metallic case the pairs would most likely form in an anisotropic state, and would then lead in this neutral system to superfluidity. However, what had not been anticipated was the richness of the phenomena which would be revealed by the experiments of 1972. In the first place, even in a zero magnetic field there is not one but two superfluid phases, and the explanation of this involves ideas concerning "spin fluctuation feedback" which have no obvious analog in metals. Secondly, the anisotropic nature of the pair wave function, which in the case of the B phase is quite subtle, and the fact that the orientation must be the same for all the pairs, leads to a number of qualitatively new effects, in particular to a spectacular amplification of ultra-weak interactions seen most dramatically in the NMR behavior. In this chapter I review the application of BCS theory to superfluid 3- He with emphasis on these novel features.

Independent gradient model based on Hirshfeld partition (IGMH): A new method for visual study of interactions in chemical systems

2021 ◽  
Author(s):  
Tian Lu ◽  
Qinxue Chen
Keyword(s):  
Visual Analysis ◽  
Weak Interactions ◽  
Chem Phys ◽  
Noncovalent Interaction ◽  
Chemical Systems ◽  
Gradient Model ◽  
Atom Pairs ◽  
New Variant ◽  
Physical Background ◽  
User Friendly

The independent gradient model (IGM) originally proposed in Phys. Chem. Chem. Phys., 19, 17928 (2017) has been increasingly popular in visual analysis of intramolecular and intermolecular interactions in recent years, and it has many clear advantages over the widely employed noncovalent interaction (NCI) method, such as intrafragment and interfragment interactions can be elegantly isolated and thus separately studied, the isosurfaces are smoother and less jaggy. However, we frequently observed that there is an evident shortcoming of IGM map in graphically studying weak interactions, that is its isosurfaces are usually too bulgy; in these cases, not only the graphical effect is poor, but also the color on some areas on the isosurfaces is inappropriate and may lead to erroneous analysis conclusions. In addition, the IGM method was originally proposed based on promolecular density, which is quite crude and does not take actual electronic structure into account. In this article, we first present a detailed overview of the IGM analysis, and then propose our new variant of IGM, namely IGM based on Hirshfeld partition of molecular density (IGMH), which replaces the free-state atomic densities involved in the IGM method with the atomic densities derived by Hirshfeld partition of actual molecular electron density. This change makes IGM have more rigorous physical background. In addition, we describe some indices defined on the top of IGM or IGMH framework to quantify contributions from various atoms or atom pairs to interaction between specific fragments. A large number of application examples in this article, including molecular and periodic systems, weak and chemical bond interactions, fully demonstrate the important value of IGMH in intuitively understanding interactions in chemical systems. Comparisons also showed that the IGMH usually has markedly better graphical effect than IGM and overcomes known problems in IGM. Currently IGMH analysis has been efficiently supported in our freely available and user-friendly wavefunction analysis code Multiwfn (http://sobereva.com/multiwfn), and a detailed tutorial is presented. We hope that IGMH will become a new popular method among chemists for exploring interactions in wide variety of chemical systems.

scholarly journals Independent gradient model based on Hirshfeld partition (IGMH): A new method for visual study of interactions in chemical systems

2021 ◽  
Author(s):  
Tian Lu ◽  
Qinxue Chen
Keyword(s):  
Visual Analysis ◽  
Weak Interactions ◽  
Chem Phys ◽  
Noncovalent Interaction ◽  
Chemical Systems ◽  
Gradient Model ◽  
Atom Pairs ◽  
New Variant ◽  
Physical Background ◽  
User Friendly

The independent gradient model (IGM) originally proposed in Phys. Chem. Chem. Phys., 19, 17928 (2017) has been increasingly popular in visual analysis of intramolecular and intermolecular interactions in recent years, and it has many clear advantages over the widely employed noncovalent interaction (NCI) method, such as intrafragment and interfragment interactions can be elegantly isolated and thus separately studied, the isosurfaces are smoother and less jaggy. However, we frequently observed that there is an evident shortcoming of IGM map in graphically studying weak interactions, that is its isosurfaces are usually too bulgy; in these cases, not only the graphical effect is poor, but also the color on some areas on the isosurfaces is inappropriate and may lead to erroneous analysis conclusions. In addition, the IGM method was originally proposed based on promolecular density, which is quite crude and does not take actual electronic structure into account. In this article, we first present a detailed overview of the IGM analysis, and then propose our new variant of IGM, namely IGM based on Hirshfeld partition of molecular density (IGMH), which replaces the free-state atomic densities involved in the IGM method with the atomic densities derived by Hirshfeld partition of actual molecular electron density. This change makes IGM have more rigorous physical background. In addition, we describe some indices defined on the top of IGM or IGMH framework to quantify contributions from various atoms or atom pairs to interaction between specific fragments. A large number of application examples in this article, including molecular and periodic systems, weak and chemical bond interactions, fully demonstrate the important value of IGMH in intuitively understanding interactions in chemical systems. Comparisons also showed that the IGMH usually has markedly better graphical effect than IGM and overcomes known problems in IGM. Currently IGMH analysis has been efficiently supported in our freely available and user-friendly wavefunction analysis code Multiwfn (http://sobereva.com/multiwfn), and a detailed tutorial is presented. We hope that IGMH will become a new popular method among chemists for exploring interactions in wide variety of chemical systems.

Correlated-Wave-Function Calculation of the Chemisorption of CO on Ti(0001)

1982 ◽  
Vol 49 (5) ◽  
pp. 344-347 ◽  
Author(s):  
C. R. Fischer ◽  
L. A. Burke ◽  
J. L. Whitten
Keyword(s):  
Wave Function ◽  
Function Calculation

Electronic wave functions - The evaluation of the general vector-coupling coefficients by automatic computation

1954 ◽  
Vol 246 (917) ◽  
pp. 463-479 ◽  
Keyword(s):  
Wave Function ◽  
Wave Functions ◽  
Coupling Coefficients ◽  
Easy Method ◽  
Atomic Wave Function ◽  
Vector Coupling ◽  
Method Of Calculation ◽  
Different Types ◽  
Function Calculation ◽  
Method Of Evaluation

A considerable number of different types of investigations on atomic and nuclear wave functions involve the use of vector-coupled functions and would be facilitated by an easy method of evaluation of the basic fundamental coefficients. This is particularly so for the present series of investigations, in which very complicated vector-coupled functions are used in convergent methods of atomic wave-function calculation. Hitherto the evaluation of these coefficients, which are independent of all aspects of a problem other than the irreducible representations of the rotational group concerned, has been extremely tedious while still requiring considerable mathematical understanding. It has now been found possible to develop a method of calculation which can be performed purely automatically by the EDSAC, proceeding from the lowest argument values indefinitely through all higher values. A substantial table, which would otherwise require over a year of computation by a mathematician, has been obtained. This investigation constitutes a significant contribution to problems of wave-function calculation and also involves some minor innovations in the vector-coupling theory.

Convergent S. C. F. Wave Function and Properties of the Ammonia Molecule

1965 ◽  
Vol 20 (12) ◽  
pp. 1557-1565 ◽  
Author(s):  
P. Rajagopal
Keyword(s):  
Wave Function ◽  
Ammonia Molecule ◽  
Quadrupole Moments ◽  
Dissociation Energies ◽  
Self Consistent Field ◽  
Molecular Integrals ◽  
Function Calculation ◽  
F Wave ◽  
Numerical Integration Methods ◽  
Field Wave

A self consistent field wave function calculation for the ammonia molecule by the technique of accumulative accuracy is described. The molecular integrals required are calculated by numerical integration methods. Total and dissociation energies, dipole and quadrupole moments and ionization potentials calculated using the wave function are reported. The proton affinity of NH3 is also estimated.

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