scholarly journals Cover Picture: New Method to Study Ion-Molecule Reactions at Low Temperatures and Application to the H2++H2→H3++H Reaction (ChemPhysChem 22/2016)

ChemPhysChem ◽  
2016 ◽  
Vol 17 (22) ◽  
pp. 3578-3578 ◽  
Author(s):  
Pitt Allmendinger ◽  
Johannes Deiglmayr ◽  
Otto Schullian ◽  
Katharina Höveler ◽  
Josef A. Agner ◽  
...  
Keyword(s):  
Low Temperatures ◽  
New Method ◽  
Ion Molecule Reactions

scholarly journals New Method to Study Ion-Molecule Reactions at Low Temperatures and Application to the H2++H2→H3++H Reaction

ChemPhysChem ◽  
2016 ◽  
Vol 17 (22) ◽  
pp. 3580-3580
Author(s):  
Pitt Allmendinger ◽  
Johannes Deiglmayr ◽  
Otto Schullian ◽  
Katharina Höveler ◽  
Josef A. Agner ◽  
...  
Keyword(s):  
Low Temperatures ◽  
New Method ◽  
Ion Molecule Reactions

scholarly journals New Method to Study Ion-Molecule Reactions at Low Temperatures and Application to the H2++H2→H3++H Reaction

ChemPhysChem ◽  
2016 ◽  
Vol 17 (22) ◽  
pp. 3596-3608 ◽  
Author(s):  
Pitt Allmendinger ◽  
Johannes Deiglmayr ◽  
Otto Schullian ◽  
Katharina Höveler ◽  
Josef A. Agner ◽  
...  
Keyword(s):  
Low Temperatures ◽  
New Method ◽  
Ion Molecule Reactions

Molecular-physics aspects of cold chemistry

2019 ◽  
pp. 82-141
Author(s):  
FrÉdÉric Merkt
Keyword(s):  
Low Temperature ◽  
Low Temperatures ◽  
Molecular Physics ◽  
Exothermic Reactions ◽  
Langevin Model ◽  
Ion Molecule Reactions ◽  
Radiative Association ◽  
Association Reaction ◽  
Oppenheimer Approximation ◽  
General Aspects

Molecular-physics aspects of cold chemistry are introduced with the example of few-electron molecules. After a brief overview of general aspects of molecular physics, the solution of the molecular Schrödinger equation is presented based on the Born-Oppenheimer approximation and the subsequent evaluation of adiabatic, nonadiabatic, relativistic and radiative (QED) corrections. Low-temperature chemical phenomena are introduced with the example of ion-molecule reactions, using the classical Langevin model for barrier-free exothermic reactions as reference. Then, methods to generate cold few-electron molecules by supersonic-beam-deceleration methods such as Stark, Zeeman, and Rydberg-Stark decelerations are presented. Two astrophysically important reactions, the reaction between H2 and H2+ forming H3+ and H, a very fast reaction following Langevin-capture going over to quantum-Langevin capture at low temperature, and the radiative association reaction H+ + H forming H2+, a very slow reaction in which quantum effects (shape resonances) become important at low temperatures, are used to illustrate the concepts introduced.

New method for reducing the general formula for lattice specific heat to the Einstein and Nernst-Lindemann approximations

2003 ◽  
Vol 81 (8) ◽  
pp. 1015-1036 ◽  
Author(s):  
F E Irons
Keyword(s):  
Specific Heat ◽  
General Formula ◽  
Low Temperatures ◽  
Present Theory ◽  
New Method ◽  
Simple Extension ◽  
Lattice Specific Heat ◽  
Modes Of Vibration ◽  
Mathematical Approximation ◽  
Real Solid

To reduce the general formula for lattice specific heat to Einstein's formula of 1907, one traditionally models the spectrum of lattice modes-of-vibration as a set of independent oscillators all of one frequency, ν1. Not only is this a poor representation of a real solid, but no formula is provided for the frequency ν1, which has to be determined empirically. We offer a new and more compelling method for reducing the general formula to Einstein's formula. The reduction involves a simple mathematical approximation, proceeds without any reference to independent oscillators all of one frequency, and leads to a formula for the characteristic frequency, ν1, equal to the mean modal frequency. The mathematical approximation is valid at all but low temperatures, thereby providing insight into the failure of Einstein's formula at low temperatures. A simple extension of the new method leads to the Nernst–Lindemann formula for specific heat, proposed in 1911 on the basis of trial and error and currently without a sound theoretical basis. Empirical values (from the literature) of the frequencies that characterize the Einstein, the Nernst–Lindemann, and also the Debye formulae are all in support of the present theory. PACS Nos.: 65.40.Ba, 01.55.+b

A new method for determining specific heats at extremely low temperatures

Physica ◽  
1939 ◽  
Vol 6 (3) ◽  
pp. 255-261 ◽  
Author(s):  
H.B.G. Casimir ◽  
W.J. de Haas ◽  
D. de Klerk
Keyword(s):  
Low Temperatures ◽  
New Method ◽  
Specific Heats

AN X-RAY METHOD FOR THE STUDY OF "BOUND WATER" IN HYDROPHILIC COLLOIDS AT LOW TEMPERATURES

1935 ◽  
Vol 13b (4) ◽  
pp. 218-227 ◽  
Author(s):  
W. H. Barnes ◽  
W. F. Hampton
Keyword(s):  
Qualitative Study ◽  
Low Temperatures ◽  
Bound Water ◽  
New Method ◽  
Ray Method ◽  
X Ray ◽  
Temperature Range ◽  
Methods Of Analysis ◽  
Gelatin Gels ◽  
Ray Methods

A new method for the study of hydrophilic colloids by the application of X-ray methods of analysis to the frozen gels is described. The possibilities of the method and its limitations are shown by a qualitative study of the amount, and variation with temperature, of the so-called "bound" water in gelatin gels over the temperature range − 3° to − 50 °C.

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