The Polarizability of Molecular Hydrogen H2

1936 ◽  
Vol 32 (2) ◽  
pp. 260-264 ◽  
Author(s):  
C. E. Easthope

1. The problem of calculating the polarizability of molecular hydrogen has recently been considered by a number of investigators. Steensholt and Hirschfelder use the variational method developed by Hylleras and Hassé. For ψ0, the wave function of the unperturbed molecule when no external field is present, they take either the Rosent or the Wang wave function, while the wave functions of the perturbed molecule were considered in both the one-parameter form, ψ0 [1+A(q1 + q2)] and the two-parameter form, ψ0 [1+A(q1 + q2) + B(r1q1 + r2q2)], where A and B are parameters to be varied so as to give the system a minimum energy, q1 and q2 are the coordinates of the electrons 1 and 2 in the direction of the applied field as measured from the centre of the molecule, and r1 and r2 are their respective distances from the same point. Mrowka, on the other hand, employs a method based on the usual perturbation theory. Their numerical results are given in the following table.

information. How do produced quantities influence the costs per unit? How can costs, calculated at different times, be compared? What is the best way to distribute the overheads? etc.. .. After the setting up of the accounting system, a long process of maturation began. This is evident, on the one hand, from the discussions of the Board of Directors and, on the other hand from the differences between the two sets of accounts approved by the Board of Directors in 1832 and 1872. The structure of the Com­ pany evolved considerably between 1832 and 1880: two mergers occurred, the first one in 1858 with Saint-Quirin, a glass manufac­ turer, and the second one in 1872 with Perret-Olivier, whose fields of activity were mining and chemistry. After the second merger, the sales figures for chemistry outstripped the sales of glass and mirrors and during this time the Company had grown to include 16 branches in France and Germany. DISCUSSIONS ON INDUSTRIAL ACCOUNTING All the questions dealing with the setting up of a management accounting system were discussed by the Boards of Directors. In most cases, the solutions were only practical ones. There never seemed any intent or desire by the Company to make any theory or any generalization of those practical solutions. Direct and indirect costs. The distinction between direct and indirect cost was made first in 1829 with regards to labor charges.9 Salaries, of which a comprehensive list is given above, will be separated into two groups: 1) Those concerning directly and specially with the manufacturing process. 2) Those concerning administration. At the end of the year, the former will be divided and included in the suitable items of expenses; then the latter will be included in the overheads. However, direct labor is likely to have included only the wages of workers having a permanent job, and excluded those of the day laborer, which are by their very nature fluctuating. In the soda factory, the majority of workers were day laborers, thus making it difficult to estimate precisely the ratio between direct and indirect labor charges. Production level and cost per unit. In the previously quoted chief accountant’s report concerning the financial year 1827-1828,

2014 ◽  
pp. 259-259

Author(s):  
W. E. Duncanson

The momentum distribution for the electron in the hydrogen molecular ion has been calculated for various wave functions, including the one used by James with which he obtained such a good value for the binding energy. The method adopted for this particular wave function is outlined and the results show appreciable change with improvement in the wave function. In conclusion there are discussed the implications of the present calculations on similar work on the H2 molecule.


Author(s):  
Bhagyshree Pravin Bhure ◽  
Pratiksha Tulshiram Bansod ◽  
Monali Shivram Amgaokar ◽  
Savita Pralhad Lodiwale ◽  
Anjali Pravin Orkey ◽  
...  

With the quick rise in living standards, people's shopping passion grew, and their desire for clothing grew as well. A growing number of people are interested in fashion these days. However, when confronted with a large number of garments, consumers are forced to try them on multiple times, which takes time and energy. As a result of the suggested Fashion Recommendation System, a variety of online fashion businesses and web applications allow buyers to view collages of stylish items that look nice together. Clients and sellers benefit from such recommendations. On the one hand, customers can make smarter shopping decisions and discover new articles of clothes that complement one other. Complex outfit recommendations, on the other hand, assist vendors in selling more products, which has an impact on their business. FashionNet is made up of two parts: a feature network for extracting features and a matching network for calculating compatibility. A deep convolutional network is used to achieve the former. For the latter, a multi-layer completely connected network topology is used. For FashionNet, you must create and compare three different architectures. To achieve individualised recommendations, a two-stage training technique was created.


1996 ◽  
Vol 11 (03) ◽  
pp. 257-266 ◽  
Author(s):  
TAKAYUKI MATSUKI

Operating just once the naive Foldy-Wouthuysen-Tani transformation on the Schrödinger equation for [Formula: see text] bound states described by a Hamiltonian, we systematically develop a perturbation theory in 1/mQ which enables one to solve the Schrödinger equation to obtain masses and wave functions of the bound states in any order of 1/mQ. There also appear negative components of the wave function in our formulation which contribute also to higher order corrections to masses.


Author(s):  
J. E. Lennard-Jones

1. The wave function of an atom containing many electrons has not yet been solved completely, even that of helium being as yet unknown. In the absence of a direct solution of the Schrödinger equation for the electrons in an atom, various attempts have been made to devise approximate methods of solution in particular cases. The particular case of helium, being the easiest, has received considerable attention and a number of approximate wave functions appropriate to the normal state have been constructed. These functions usually contain empirical constants which are adjusted to make the energy of the system a minimum. Zener has attempted the more ambitious programme of finding the wave functions of all the atoms in the first period of the Periodic Table (Lithium to Neon), and has made interesting discoveries as to the way in which the wave functions differ from atom to atom. This work also is based on the variation of parameters.


1995 ◽  
Vol 05 (01) ◽  
pp. 3-16 ◽  
Author(s):  
ILYA PRIGOGINE

Nonintegrable Poincaré systems with continuous spectrum (so-called Large Poincaré Systems, LPS) lead to the appearance of diffusive terms in the framework of dynamics. These terms break time symmetry. They lead, therefore, to limitations to classical trajectory dynamics and of wave functions. These diffusive terms correspond to well-defined classes of dynamical processes (i.e., so-called “vacuum-vacuum” transitions). The diffusive effects are amplified in situations corresponding to persistent interactions. As a result, we have to include already in the fundamental dynamical description the two aspects, probability and irreversibility, which are so conspicuous on the macroscopic level. We have to formulate both classical and quantum mechanics on the Liouville level of probability distributions (or density matrices). For integrable systems, we recover the usual formulations of classical or quantum mechanics. Instead of being irreducible concepts, which cannot be further analyzed, trajectories and wave functions appear as special solutions of the Liouville-von Neumann equations. This extension of classical and quantum dynamics permits us to unify the two concepts of nature we inherited from the 19th century, based on the one hand on dynamical time-reversible laws and on the other on an evolutionary view associated to entropy. It leads also to a unified formulation of quantum theory avoiding the conventional dual structure based on Schrödinger’s equation on the one hand, and on the “collapse” of the wave function on the other. A dynamical interpretation is given to processes such as decoherence or approach to equilibrium without any appeal to extra dynamic considerations (such as the many-world theory, coarse graining or averaging over the environment). There is a striking parallelism between classical and quantum theory. For LPS we have, in general, both a “collapse” of trajectories and of wave functions for LPS. In both cases, we need a generalized formulation of dynamics in terms of probability distributions or density matrices. Since the beginning of this century, we know that classical mechanics had to be generalized to take into account the existence of universal constants. We now see that classical as well as quantum mechanics also have to be extended to include unstable dynamical systems such as LPS. As a result, we achieve a new formulation of "laws of physics" dealing no more with certitudes but with probabilities. The formulation is appropriate to describe an open, evolving universe.


Previous ideas about the way in which hypervirial theorems might be used to improve approximate wave functions are discussed. To provide a firmer foundation for these ideas, a link is established between hypervirial theorems and perturbation theory. It is proved that if the first-order perturbation correction to the expectation value of an arbitrary operator vanishes, then the approximate wave function used satisfies a certain hypervirial theorem. Conversely, if an arbitrary hypervirial theorem is satisfied by the wave function, then it is proved that the expectation values of certain operators have vanishing first-order corrections. Some consequences of the theory as applied to variational wave functions with optimum energy are developed. The results are illustrated by the use of a simple approximate wave function for the ground state of the helium atom.


2013 ◽  
Vol 68 (10-11) ◽  
pp. 709-714 ◽  
Author(s):  
Mohammadreza Pahlavani ◽  
Behnam Firoozi

Energy spectrum and wave functions are obtained numerically with a potential consisting of Woods-Saxon, Coulomb, and spin-orbit coupling parts for the nuclei 15O, 15N, 17O, and 17F. The radial parts of the wave functions are used to calculate some matrix elements of electromagnetic transitions. These results are applied to calculate half-lives of low-lying exited states in the one-particle 17O and 17F as well as in the one-hole 15O and 15N isotopes. The calculated half-lives are compared with available experimental and theoretical results based on harmonic oscillator wave functions and Weisskopf units. In comparison with the results calculated from the other methods, our results based on the Woods-Saxon potential indicate a satisfactory agreement with accessible experimental data.


1977 ◽  
Vol 55 (5) ◽  
pp. 396-402 ◽  
Author(s):  
Madeleine M. Felden ◽  
Marceau A. Felden

Ochkur's approximation is used to analyse the excitation of 21S and 23S levels of helium atoms from the ground state by electron and hydrogen atom impact. Calculations are made with different atomic wave functions. To characterize the 11S and 21S states we use, on the one hand, the wave functions of Byron and Joachain, on the other hand, those of Hylleraas and Marriott and Seaton. For the 11S and 23S states, calculations are made firstly with the wave functions of Byron and Joachain and Morse, Young, and Haurwitz, secondly with those of Shull and Lödwin. Numerical values are tabulated and compared in each case. The discrepancies show the importance of the choice of atomic wave functions in the calculation of the excitation cross sections. Available experimental data and corresponding theoretical values obtained from other theories are plotted and compared with the present results.


2013 ◽  
Vol 22 (05) ◽  
pp. 1330012 ◽  
Author(s):  
SINYA AOKI ◽  
JANOS BALOG ◽  
TAKUMI DOI ◽  
TAKASHI INOUE ◽  
PETER WEISZ

We review recent investigations on the short distance behaviors of potentials among baryons, which are formulated through the Nambu–Bethe–Salpeter (NBS) wave function. After explaining the method to define the potentials, we analyze the short distance behavior of the NBS wave functions and the corresponding potentials by combining the operator product expansion (OPE) and a renormalization group (RG) analysis in the perturbation theory (PT) of QCD. These analytic results are compared with numerical results obtained in lattice QCD simulations.


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