DOI: 10.7910/dvn/amem0w
title: CTC results and rotational relaxation model for nitrogen and oxygen

description: &lt;h3&gt;Abstract&lt;/h3&gt; 
&lt;p&gt;The dataset contains: 
&lt;ul&gt;
&lt;li&gt;Results of classical trajectory calculations (CTC) of binary intermolecular collisions of the following pairs of diatomic molecules:
 &lt;ul&gt;
 &lt;li&gt;N2 - N2&lt;/li&gt;
 &lt;li&gt;N2 - O2 (will be published soon)&lt;/li&gt;
 &lt;li&gt;O2 - O2 (will be published soon)&lt;/li&gt;
 &lt;/ul&gt;
&lt;/li&gt;
&lt;li&gt;Collision model code (C++ class)

&lt;/li&gt;
&lt;/ul&gt;
&lt;/p&gt; 

&lt;h3&gt;Related Publication&lt;/h3&gt; 
&lt;p&gt;&lt;i&gt;Artem Yakunchikov, Vasily Kosyanchuk, Aliya Iuldasheva, Microscopic rotational relaxation model for nitrogen and its application in free jet expansion problem (paper is under review)&lt;/i&gt; 
&lt;/p&gt; 

&lt;h3&gt;1. Results CTC of binary collisions&lt;/h3&gt; 
&lt;p&gt;Files with the results of calculations are placed in the "CTC results" folder, then you need to select the folder corresponding to the desired colliding pair of molecules. Inside there are files of the form &lt;b&gt;"md_distr_XX.csv"&lt;/b&gt;, where XX corresponds to the following parameter P after collision:
&lt;ul&gt;
&lt;li&gt;00: γ'_r&lt;/li&gt;
&lt;li&gt;01: γ'_1&lt;/li&gt;
&lt;li&gt;07: g'_x, m/s&lt;/li&gt;
&lt;li&gt;08: g'_y, m/s&lt;/li&gt;
&lt;li&gt;09: g'_z, m/s&lt;/li&gt;
&lt;/ul&gt;
&lt;/p&gt;
&lt;p&gt;List of fields inside a file: 
&lt;ul&gt;
&lt;li&gt;ε/k, K
&lt;li&gt;b, A
&lt;li&gt;γ_r
&lt;li&gt;γ_1
&lt;li&gt;Mean value of the P
&lt;li&gt;After the symbol "d", the probability density for P is stored
&lt;/ul&gt;
&lt;/p&gt;

&lt;h3&gt;2. Collision model code&lt;/h3&gt; 
&lt;p&gt;The proposed collision model was implemented as a C++ class: &lt;b&gt;airpotentials.h&lt;/b&gt; (see folder "Collision model")&lt;/p&gt;

&lt;p&gt;Before use, it is necessary to initialize once the model from the file:&lt;/p&gt; 
&lt;pre&gt;
 #include "collisionmodel.h"
 
 // Model class
 collisionmodel cm;

 // Init model from file
 cm.LoadModelFromFile("collmodel_N2_N2.txt");
&lt;/pre&gt; 
&lt;p&gt;To calculate the post-collision parameters of the colliding molecules, you need to call the function
 &lt;i&gt;ComputeCollision(...)&lt;/i&gt; with the the pre-collision parameters as arguments:&lt;/p&gt; 
&lt;pre&gt;
 // Pre-collision values
 double b = ...;
 double er_before = ...;
 double ein_before[2] = {...};

 // Post-collision values
 double er_after, ein_after[2], chi;

 // Compute post-collision parameters
 cm.ComputeCollision(b, er_before, ein_before, &er_after, ein_after, &chi);
&lt;/pre&gt; 

&lt;h3&gt;Acknowledgments&lt;/h3&gt; 
&lt;p&gt;The research is carried out using the equipment of the shared research facilities of &lt;a href="https://parallel.ru/" target="_blank" rel="nofollow"&gt;HPC computing resources at Lomonosov Moscow State University&lt;/a&gt; and Joint Supercomputer Center of the Russian Academy of Sciences. The research was supported by the &lt;a href="https://www.rfbr.ru/rffi/ru/" target="_blank" rel="nofollow"&gt;Russian Foundation for Basic Research&lt;/a&gt; (project № 18-31-20025).&lt;/p&gt;