Christina Castro , Kyle Doan , Michael Klemka , Robert C. Forrey , Benhui Yang , Phillip C. Stancil , N. Balakrishnan
{"title":"CO和H2碰撞的非弹性截面和速率系数","authors":"Christina Castro , Kyle Doan , Michael Klemka , Robert C. Forrey , Benhui Yang , Phillip C. Stancil , N. Balakrishnan","doi":"10.1016/j.molap.2017.01.003","DOIUrl":null,"url":null,"abstract":"<div><p>A five-dimensional coupled states (5D-CS) approximation is used to compute cross sections and rate coefficients for CO+H<sub>2</sub> collisions. The 5D-CS calculations are benchmarked against accurate six-dimensional close-coupling (6D-CC) calculations for transitions between low-lying rovibrational states. Good agreement between the two formulations is found for collision energies greater than 10<!--> <!-->cm<sup>−1</sup>. The 5D-CS approximation is then used to compute two separate databases which include highly excited states of CO that are beyond the practical limitations of the 6D-CC method. The first database assumes an internally frozen H<sub>2</sub> molecule and allows rovibrational transitions for <em>v</em> ≤ 5 and <em>j</em> ≤ 30, where <em>v</em> and <em>j</em><span> are the vibrational and rotational quantum numbers of the initial state of the CO molecule. The second database allows H</span><sub>2</sub><span> rotational transitions for initial CO states with </span><em>v</em> ≤ 5 and <em>j</em> ≤ 10. The two databases are in good agreement with each other for transitions that are common to both basis sets. Together they provide data for astrophysical models which were previously unavailable.</p></div>","PeriodicalId":44164,"journal":{"name":"Molecular Astrophysics","volume":"6 ","pages":"Pages 47-58"},"PeriodicalIF":0.0000,"publicationDate":"2017-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.molap.2017.01.003","citationCount":"6","resultStr":"{\"title\":\"Inelastic cross sections and rate coefficients for collisions between CO and H2\",\"authors\":\"Christina Castro , Kyle Doan , Michael Klemka , Robert C. Forrey , Benhui Yang , Phillip C. Stancil , N. Balakrishnan\",\"doi\":\"10.1016/j.molap.2017.01.003\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>A five-dimensional coupled states (5D-CS) approximation is used to compute cross sections and rate coefficients for CO+H<sub>2</sub> collisions. The 5D-CS calculations are benchmarked against accurate six-dimensional close-coupling (6D-CC) calculations for transitions between low-lying rovibrational states. Good agreement between the two formulations is found for collision energies greater than 10<!--> <!-->cm<sup>−1</sup>. The 5D-CS approximation is then used to compute two separate databases which include highly excited states of CO that are beyond the practical limitations of the 6D-CC method. The first database assumes an internally frozen H<sub>2</sub> molecule and allows rovibrational transitions for <em>v</em> ≤ 5 and <em>j</em> ≤ 30, where <em>v</em> and <em>j</em><span> are the vibrational and rotational quantum numbers of the initial state of the CO molecule. The second database allows H</span><sub>2</sub><span> rotational transitions for initial CO states with </span><em>v</em> ≤ 5 and <em>j</em> ≤ 10. The two databases are in good agreement with each other for transitions that are common to both basis sets. Together they provide data for astrophysical models which were previously unavailable.</p></div>\",\"PeriodicalId\":44164,\"journal\":{\"name\":\"Molecular Astrophysics\",\"volume\":\"6 \",\"pages\":\"Pages 47-58\"},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2017-03-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://sci-hub-pdf.com/10.1016/j.molap.2017.01.003\",\"citationCount\":\"6\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Molecular Astrophysics\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S2405675816300446\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"Physics and Astronomy\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Molecular Astrophysics","FirstCategoryId":"1085","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S2405675816300446","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"Physics and Astronomy","Score":null,"Total":0}
Inelastic cross sections and rate coefficients for collisions between CO and H2
A five-dimensional coupled states (5D-CS) approximation is used to compute cross sections and rate coefficients for CO+H2 collisions. The 5D-CS calculations are benchmarked against accurate six-dimensional close-coupling (6D-CC) calculations for transitions between low-lying rovibrational states. Good agreement between the two formulations is found for collision energies greater than 10 cm−1. The 5D-CS approximation is then used to compute two separate databases which include highly excited states of CO that are beyond the practical limitations of the 6D-CC method. The first database assumes an internally frozen H2 molecule and allows rovibrational transitions for v ≤ 5 and j ≤ 30, where v and j are the vibrational and rotational quantum numbers of the initial state of the CO molecule. The second database allows H2 rotational transitions for initial CO states with v ≤ 5 and j ≤ 10. The two databases are in good agreement with each other for transitions that are common to both basis sets. Together they provide data for astrophysical models which were previously unavailable.
期刊介绍:
Molecular Astrophysics is a peer-reviewed journal containing full research articles, selected review articles, and thematic issues. Molecular Astrophysics is a new journal where researchers working in planetary and exoplanetary science, astrochemistry, astrobiology, spectroscopy, physical chemistry and chemical physics can meet and exchange their ideas. Understanding the origin and evolution of interstellar and circumstellar molecules is key to understanding the Universe around us and our place in it and has become a fundamental goal of modern astrophysics. Molecular Astrophysics aims to provide a platform for scientists studying the chemical processes that form and dissociate molecules, and control chemical abundances in the universe, particularly in Solar System objects including planets, moons, and comets, in the atmospheres of exoplanets, as well as in regions of star and planet formation in the interstellar medium of galaxies. Observational studies of the molecular universe are driven by a range of new space missions and large-scale scale observatories opening up. With the Spitzer Space Telescope, the Herschel Space Observatory, the Atacama Large Millimeter/submillimeter Array (ALMA), NASA''s Kepler mission, the Rosetta mission, and more major future facilities such as NASA''s James Webb Space Telescope and various missions to Mars, the journal taps into the expected new insights and the need to bring the various communities together on one platform. The journal aims to cover observational, laboratory as well as computational results in the galactic, extragalactic and intergalactic areas of our universe.