A perspective on quantum mechanics and chemical concepts in describing noncovalent interactions

2018 ◽  
Vol 20 (48) ◽  
pp. 30076-30082 ◽  
Author(s):  
Timothy Clark ◽  
Jane S. Murray ◽  
Peter Politzer
Keyword(s):  
Quantum Mechanics ◽  
Charge Transfer ◽  
Mathematical Modelling ◽  
Noncovalent Interactions ◽  
Physical Reality ◽  
Quantum Mechanical ◽  
Quantum Mechanical Calculations ◽  
Resonance Theory ◽  
Chemical Concepts ◽  
Octet Rule

Since quantum mechanical calculations do not typically lend themselves to chemical interpretation, analyses of bonding interactions depend largely upon models (the octet rule, resonance theory, charge transfer, etc.). This sometimes leads to a blurring of the distinction between mathematical modelling and physical reality.

On the error of approximations in quantum mechanics. I. General theory

1965 ◽  
Vol 257 (1081) ◽  
pp. 309-326 ◽  
Keyword(s):  
Quantum Mechanics ◽  
General Theory ◽  
Computer Applications ◽  
Quantum Mechanical ◽  
Quantum Mechanical Calculations ◽  
Density Matrices ◽  
Single Error

General formulas for estimating the errors in quantum-mechanical calculations are given in the formalism of density matrices. Some properties of the traces of matrices are used to simplify the estimating and to indicate a way of obtaining a better approximation. It is shown that the simultaneous correction of all the equations to be fulfilled leads in most cases to a faster convergence than the exact fulfilment of some of the equations and approximating stepwise to some of the others. The corrective formulas contain only direct operations of the matrices occurring and so they are advantageous in computer applications. In the last section a ‘subjective error’ definition is given and by taking into account the weight of the errors of the several equations a faster convergence and a single error quantity is obtained. Some special applications of the method will be published later.

In situ AFM and XPS Investigation of U6+ Reduction by Fe2+ on Hematite and Pyrite

2012 ◽  
Vol 1444 ◽  
Author(s):  
Jingjie Niu ◽  
Udo Becker ◽  
Rodney Ewing
Keyword(s):  
Charge Transfer ◽  
Co Adsorption ◽  
Reduction Rate ◽  
Mulliken Charge ◽  
Quantum Mechanical ◽  
Quantum Mechanical Calculations ◽  
Initial Ph ◽  
Adsorption Reduction ◽  
Tapping Mode Afm

ABSTRACTUranyl adsorption/reduction by Fe2+ on hematite and pyrite has been studied at neutral pH under anoxic and CO2-free conditions. XPS results confirm that more U3O8 precipitates on hematite than on pyrite reacted for 24 h in 160 μM uranyl nitrate and 160 μM Fe2+ solution at initial pH 7.3. These results are explained in terms of co-adsorption energy and U atom Mulliken charge transfer by quantum mechanical calculations. Moreover, in situ fluid tapping-mode AFM experiments on hematite indicate a deceleration of the U reduction rate within 24 h due to the passivation of the surface caused by the formation of orthorhombic U3O8 crystals. In addition, crystals observed using AFM show morphologies of orthorhombic schoepite appearing on hematite after 5 h.

scholarly journals Did bohr succeed in defending the completeness of quantum mechanics?

2020 ◽  
Vol 24 (1) ◽  
pp. 51-63
Author(s):  
Kunihisa Morita
Keyword(s):  
Wave Function ◽  
Quantum Mechanics ◽  
Recent Trend ◽  
Physical Reality ◽  
Current Paper ◽  
Quantum Mechanical ◽  
Mechanical Description ◽  
Quantum Mechanical Description ◽  
Completeness Of Quantum Mechanics

This study posits that Bohr failed to defend the completeness of the quantum mechanical description of physical reality against Einstein–Podolsky–Rosen’s (EPR) paper. Although there are many papers in the literature that focus on Bohr’s argument in his reply to the EPR paper, the purpose of the current paper is not to clarify Bohr’s argument. Instead, I contend that regardless of which interpretation of Bohr’s argument is correct, his defense of the quantum mechanical description of physical reality remained incomplete. For example, a recent trend in studies of Bohr’s work is to suggest he considered the wave-function description to be epistemic. However, such an interpretation cannot be used to defend the completeness of the quantum mechanical description.

scholarly journals Predicting crystal structures and properties of matter under extreme conditions via quantum mechanics: the pressure is on

2015 ◽  
Vol 17 (5) ◽  
pp. 2917-2934 ◽  
Author(s):  
Eva Zurek ◽  
Wojciech Grochala
Keyword(s):  
Quantum Mechanics ◽  
Crystal Structures ◽  
Quantum Mechanical ◽  
Extreme Conditions ◽  
Quantum Mechanical Calculations ◽  
Structures And Properties

The role of quantum mechanical calculations in understanding and predicting the behavior of matter at extreme pressures is discussed in this feature contribution.

scholarly journals Quantum Statistics in Cylindrical Time-evolution of Electrons and Physical Reality

2020 ◽  
Vol 36 (3) ◽  
Author(s):  
Vo Van Thuan ◽  
Dao Dinh Duc
Keyword(s):  
Quantum Mechanics ◽  
Plane Wave ◽  
Minkowski Space ◽  
Time Evolution ◽  
Physical Reality ◽  
Space Time ◽  
Quantum Mechanical ◽  
Minkowski Space Time ◽  
Short Time ◽  
Physical Quantities

Due to helical cylindrical time-evolution of electrons the mankind observation at a quantum mechanical scale depends on synchronization between observers and their surrounding cosmological medium by collective dynamics. From one side, the synchronization leads to linearization of an embedded 4D space-time reminiscent of the flat Minkowski space-time. From another side, variation of the synchronization due to independent proper plane wave oscillations of each electron being constrained in a short time quantized period, implies that there only statistical averaged physical quantities are observable, which is in consistency with statistical indeterministic concept of traditional quantum mechanics.

Quantum-mechanical calculations of charge transfer in collisions ofO3+with He

2009 ◽  
Vol 79 (6) ◽  
Author(s):  
Y. Wu ◽  
Y. Y. Qi ◽  
S. Y. Zou ◽  
J. G. Wang ◽  
Y. Li ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Quantum Mechanical ◽  
Quantum Mechanical Calculations

Significance of hydrogen bonding networks in the proton-coupled electron transfer reactions of photosystem II from a quantum-mechanics perspective

2019 ◽  
Vol 21 (17) ◽  
pp. 8721-8728 ◽  
Author(s):  
Jun Chai ◽  
Zhaoyang Zheng ◽  
Hui Pan ◽  
Shengbai Zhang ◽  
K. V. Lakshmi ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Hydrogen Bonding ◽  
Quantum Mechanics ◽  
Photosystem Ii ◽  
Transfer Reactions ◽  
Quantum Mechanical ◽  
Quantum Mechanical Calculations ◽  
Electron Transfer Reactions ◽  
Proton Coupled Electron Transfer ◽  
Hydrogen Bonding Networks

All quantum-mechanical calculations provide insights into the effect of the hydrogen bonding network on the proton-coupled electron transfer at YZ and YD in photosystem II.

Chemical translators: Pauling, Wheland and their strategies for teaching the theory of resonance

1999 ◽  
Vol 32 (1) ◽  
pp. 21-46 ◽  
Author(s):  
BUHM SOON PARK
Keyword(s):  
Quantum Mechanics ◽  
Presidential Address ◽  
Three Dimensional ◽  
Chemical Society ◽  
Orbital Theory ◽  
Resonance Theory ◽  
X Ray Crystallography ◽  
Transmission Of Knowledge ◽  
Chemical Concepts ◽  
Scientific Truth

It was well said by Clerk Maxwell: ‘For the sake of persons of different types of mind scientific truth should be presented in different forms, and should be regarded as equally scientific whether it appears in the robust form and colouring of a physical illustration, or in the tenuity and paleness of a symbolical expression.’From N. V. Sidgwick's Presidential Address to the Chemical Society, London, 1937During the years between 1930 and 1950, chemistry underwent a transformation that affected both research and education. New subdisciplines like chemical physics and physical organic chemistry emerged, encouraging an influx of ideas and experimental techniques from physics. X-ray crystallography and other spectroscopic methods became indispensable for determining structures of atoms, molecules and crystals; such chemical concepts as valence and bond were refined within a new explanatory framework based on principles of physics; and the study of reaction mechanisms and rates became closely intertwined with that of structures and properties of chemical compounds. In conjunction with these changes, introductory chemical textbooks began to shift their emphasis from thermodynamic equations and solution theories to three-dimensional arrangements of atoms in molecules and types of chemical bonds. There is no doubt that the most important impetus behind this transformation was the development of quantum mechanics in the mid-1920s, and the most prominent among those who applied it to chemistry was Linus Pauling. And in Pauling's view, ‘the principal contribution of quantum mechanics to chemistry’ was the concept of resonance.The entry of resonance into chemistry, or the reception of the theory of resonance in the chemical community, has drawn considerable attention from historians of science. In particular, they have noted Pauling's flamboyant yet effective style of exposition, which became a factor in the early popularity of the resonance theory in comparison to the molecular orbital theory, another way of applying quantum mechanics to chemical problems. To be sure, the non-mathematical presentation of the resonance theory by Pauling and his collaborator, George Wheland, helped to facilitate the reception; but this presentation was vulnerable to the confusion that arose among chemists owing to the similarity between resonance and tautomerism, or between foreign and indigenous concepts. The reception occurred at the expense of serious misunderstandings about resonance. This paper investigates the ways in which Pauling and Wheland taught, and taught about, the theory of resonance, especially their ways of coping with the difficulties of translating a quantum-mechanical concept into chemical language. Their different strategies for teaching resonance theory deserve a thorough examination, not only because the strategies had to do with their solutions of the philosophical question whether resonance is a real phenomenon or not, and whether the theory of resonance is a chemical theory or a mathematical method of approximation, but also because this examination will illuminate the role of chemical translators in the transmission of knowledge across disciplinary boundaries.

Sign in / Sign up

Export Citation Format

Share Document