Vibrational Partition Function for the Multitemperature Theories of High-Temperature Flows of Gases and Plasmas

2020 ◽  
Vol 124 (20) ◽  
pp. 4048-4052 ◽  
Author(s):  
Marcin Buchowiecki
Keyword(s):  
High Temperature ◽  
Partition Function ◽  
Vibrational Partition Function

The model rotator phase

1988 ◽  
Vol 53 (5) ◽  
pp. 889-902
Author(s):  
Josef Šebek
Keyword(s):  
High Temperature ◽  
Partition Function ◽  
Conformational Flexibility ◽  
Small Probability ◽  
Crystalline Phases ◽  
Rotator Phase

It is shown that the formation of the so-called rotator phase of alkanes (one of the high temperature crystalline phases) might be connected with a partial increase of the conformational flexibility of chains. The conformations with higher number of kinks per chain, which have been neglected till now, are shown to contribute effectively to the conformational partition function. Small probability of these states given by the Boltzmann exponent is compensated by a large number of ways in which they can be distributed along the chain. The deduced features of the rotator phase seem to be in agreement with the experimentally observed properties.

RO-VIBRATIONAL PARTITION FUNCTION AND MEAN THERMAL ENERGY OF THE IMPROVED WEI OSCILLATOR

2021 ◽  
Vol 5 (1) ◽  
pp. 261-270
Author(s):  
Bako M. Bitrus ◽  
C. M. Nwabueze ◽  
J. U. Ojar ◽  
E. S. Eyube
Keyword(s):  
Partition Function ◽  
Potential Energy ◽  
Thermal Energy ◽  
Vibrational Energy ◽  
Sharp Decrease ◽  
Bound State ◽  
Solid State Physics ◽  
Absolute Deviation ◽  
Potential Energy Functions ◽  
Vibrational Partition Function

In this paper, the improved Wei oscillator has been used to model the experimental Rydberg-Klein-Rees data of the X2 Σg+ state of N2+ diatomic ions. Average absolute deviation from the dissociation energy of 0.3211% and mean absolute percentage deviation of 0.6107% were obtained. These results are quite satisfactory since they are within error requirement rate of less than 1% of the Lippincott’s criterion. Using an existing equation in the literature for bound state ro-vibrational energy, expressions for ro-vibrational partition function and mean thermal energy were derived for the improved Wei oscillator within the context of classical physics. The formulas obtained for ro-vibrational partition function and mean thermal energy were subsequently applied to the spectroscopic data of N2+ (X2 Σg+) diatomic ions. Studies have revealed that the partition function of the system decreases monotonically with decrease in temperature and increases with increase in upper bound vibrational quantum number. On the other hand, the mean thermal energies of the diatomic ions show an initial sharp decrease when the temperature is decreased and afterwards remains fairly stable as the temperature is further lowered. The results obtained in this work may find suitable applications in astrophysics were potential energy functions are required to model experimentally determined potential energy data with high precision. The work may also be useful in many other areas of physics which include: chemical physics, molecular physics, atomic physics and solid-state physics

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