{"title":"无定形固体水上 CO2 和 NO2 的形成","authors":"Meenu Upadhyay, Markus Meuwly","doi":"10.1051/0004-6361/202450091","DOIUrl":null,"url":null,"abstract":"<i>Context.<i/> The dynamics of molecule formation, relaxation, diffusion, and desorption on amorphous solid water (ASW) is studied in a quantitative fashion.<i>Aims.<i/> The formation probability, stabilization, energy relaxation, and diffusion dynamics of CO<sub>2<sub/> and NO<sub>2<sub/> on cold ASW following atom+diatom recombination reactions are characterized quantitatively.<i>Methods.<i/> Accurate machine-learned energy functions combined with fluctuating charge models were used to investigate the diffusion, interactions, and recombination dynamics of atomic oxygen with CO and NO on ASW. Energy relaxation to the ASW and into water internal degrees of freedom were determined from the analysis of the vibrational density of states. The surface diffusion and desorption energetics were investigated with extended and nonequilibrium MD simulations.<i>Results.<i/> The reaction probability is determined quantitatively and it is demonstrated that surface diffusion of the reactants on the nanosecond time scale leads to recombination for initial separations of up to 20 Å. After recombination, both CO<sub>2<sub/> and NO<sub>2<sub/> stabilize by energy transfer to water internal and surface phonon modes on the picosecond timescale. The average diffusion barriers and desorption energies agree with those reported from experiments, which validates the energy functions. After recombination, the triatomic products diffuse easily, which contrasts with the equilibrium situation, in which both CO<sub>2<sub/> and NO<sub>2<sub/> are stationary on the multinanosecond timescale.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":null,"pages":null},"PeriodicalIF":5.4000,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"CO2 and NO2 formation on amorphous solid water\",\"authors\":\"Meenu Upadhyay, Markus Meuwly\",\"doi\":\"10.1051/0004-6361/202450091\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<i>Context.<i/> The dynamics of molecule formation, relaxation, diffusion, and desorption on amorphous solid water (ASW) is studied in a quantitative fashion.<i>Aims.<i/> The formation probability, stabilization, energy relaxation, and diffusion dynamics of CO<sub>2<sub/> and NO<sub>2<sub/> on cold ASW following atom+diatom recombination reactions are characterized quantitatively.<i>Methods.<i/> Accurate machine-learned energy functions combined with fluctuating charge models were used to investigate the diffusion, interactions, and recombination dynamics of atomic oxygen with CO and NO on ASW. Energy relaxation to the ASW and into water internal degrees of freedom were determined from the analysis of the vibrational density of states. The surface diffusion and desorption energetics were investigated with extended and nonequilibrium MD simulations.<i>Results.<i/> The reaction probability is determined quantitatively and it is demonstrated that surface diffusion of the reactants on the nanosecond time scale leads to recombination for initial separations of up to 20 Å. After recombination, both CO<sub>2<sub/> and NO<sub>2<sub/> stabilize by energy transfer to water internal and surface phonon modes on the picosecond timescale. The average diffusion barriers and desorption energies agree with those reported from experiments, which validates the energy functions. After recombination, the triatomic products diffuse easily, which contrasts with the equilibrium situation, in which both CO<sub>2<sub/> and NO<sub>2<sub/> are stationary on the multinanosecond timescale.\",\"PeriodicalId\":8571,\"journal\":{\"name\":\"Astronomy & Astrophysics\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":5.4000,\"publicationDate\":\"2024-09-23\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Astronomy & Astrophysics\",\"FirstCategoryId\":\"101\",\"ListUrlMain\":\"https://doi.org/10.1051/0004-6361/202450091\",\"RegionNum\":2,\"RegionCategory\":\"物理与天体物理\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"ASTRONOMY & ASTROPHYSICS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Astronomy & Astrophysics","FirstCategoryId":"101","ListUrlMain":"https://doi.org/10.1051/0004-6361/202450091","RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ASTRONOMY & ASTROPHYSICS","Score":null,"Total":0}
引用次数: 0
摘要
背景。定量研究分子在无定形固体水(ASW)上的形成、弛豫、扩散和解吸动力学。定量表征原子+二原子重组反应后 CO2 和 NO2 在冷 ASW 上的形成概率、稳定性、能量弛豫和扩散动力学。采用精确的机器学习能量函数结合波动电荷模型,研究原子氧与 CO 和 NO 在 ASW 上的扩散、相互作用和重组动力学。通过分析振动状态密度,确定了向 ASW 和水内部自由度的能量弛豫。通过扩展和非平衡 MD 模拟研究了表面扩散和解吸的能量学。定量确定了反应概率,并证明了反应物在纳秒时间尺度上的表面扩散会导致初始分离度高达 20 Å 的重组。平均扩散障碍和解吸能与实验报告的结果一致,从而验证了能量函数。重组后,三原子产物很容易扩散,这与二氧化碳和二氧化氮在多纳秒时间尺度上都处于静止状态的平衡状态形成了鲜明对比。
Context. The dynamics of molecule formation, relaxation, diffusion, and desorption on amorphous solid water (ASW) is studied in a quantitative fashion.Aims. The formation probability, stabilization, energy relaxation, and diffusion dynamics of CO2 and NO2 on cold ASW following atom+diatom recombination reactions are characterized quantitatively.Methods. Accurate machine-learned energy functions combined with fluctuating charge models were used to investigate the diffusion, interactions, and recombination dynamics of atomic oxygen with CO and NO on ASW. Energy relaxation to the ASW and into water internal degrees of freedom were determined from the analysis of the vibrational density of states. The surface diffusion and desorption energetics were investigated with extended and nonequilibrium MD simulations.Results. The reaction probability is determined quantitatively and it is demonstrated that surface diffusion of the reactants on the nanosecond time scale leads to recombination for initial separations of up to 20 Å. After recombination, both CO2 and NO2 stabilize by energy transfer to water internal and surface phonon modes on the picosecond timescale. The average diffusion barriers and desorption energies agree with those reported from experiments, which validates the energy functions. After recombination, the triatomic products diffuse easily, which contrasts with the equilibrium situation, in which both CO2 and NO2 are stationary on the multinanosecond timescale.
期刊介绍:
Astronomy & Astrophysics is an international Journal that publishes papers on all aspects of astronomy and astrophysics (theoretical, observational, and instrumental) independently of the techniques used to obtain the results.