Ab initio studies of O 2 − (H 2 O) n and O 3 − (H 2 O) n anionic molecular clusters, n ≤12
Ab initio studies of O 2 − (H 2 O) n and O 3 − (H 2 O) n anionic molecular clusters, n ≤12
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DOI：
10.5194/acp-11-7133-2011
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发表时间：
2011-07
影响因子：
6.3
通讯作者：
N. Bork;T. Kurtén;Martin Bødker Enghoff;J. Pedersen;K. Mikkelsen;H. Svensmark
中科院分区：
文献类型：
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作者：
N. Bork;T. Kurtén;Martin Bødker Enghoff;J. Pedersen;K. Mikkelsen;H. Svensmark
抽象的。用从头算方法研究了O_2-−和O_3-−与水形成的气态团簇。基于对构型空间的彻底扫描，我们确定了团簇生长的热力学。计算结果与基准计算方法和已有实验数据吻合较好。我们发现，在典型大气条件下，O2−(H2O)n和O3−(H2O)n团簇至少在n=5时是热稳定的。前4个水分子由于过量电荷的离域而与阴离子强烈结合，而超过4H2O的稳定是由于正常的氢键。虽然团簇达到12H2O，但我们发现O2和O3负离子至少保留了约80%的电荷，并位于团簇的表面。因此，O_2-−和O_3-−谱可用于进一步的反应。在此之前，我们考虑了团簇尺寸的分布是高度的函数，最后，我们考虑了几个相关的团簇反应的热力学。
Abstract. An ab initio study of gaseous clusters of O 2 − and O 3 − with water is presented. Based on thorough scans of configurational space, we determine the thermodynamics of cluster growth. The results are in good agreement with benchmark computational methods and existing experimental data. We find that anionic O 2 − (H 2 O) n and O 3 − (H 2 O) n clusters are thermally stabilized at typical atmospheric conditions for at least n = 5. The first 4 water molecules are strongly bound to the anion due to delocalization of the excess charge while stabilization of more than 4 H 2 O is due to normal hydrogen bonding. Although clustering up to 12 H 2 O, we find that the O 2 and O 3 anions retain at least ca. 80 % of the charge and are located at the surface of the cluster. The O 2 − and O 3 − speicies are thus accessible for further reactions. We consider the distributions of cluster sizes as function of altitude before finally, the thermodynamics of a few relevant cluster reactions are considered.