Hernando Alberto, Mayol Ricardo, Pi Martí, Barranco Manuel, Ancilotto Francesco, Bünermann Oliver, Stienkemeier Frank
Departament ECM, Facultat de Física, and IN2UB, Universitat de Barcelona, Diagonal 647, 08028 Barcelona, Spain.
J Phys Chem A. 2007 Aug 9;111(31):7303-8. doi: 10.1021/jp0701385. Epub 2007 Apr 7.
We present systematic results, based on density functional calculations, for the structure and energetics of 3He and 4He nanodroplets doped with alkaline earth atoms. We predict that alkaline earth atoms from Mg to Ba go to the center of 3He drops, whereas Ca, Sr, and Ba reside in a deep dimple at the surface of 4He drops, and Mg is at their center. For Ca and Sr, the structure of the dimples is shown to be very sensitive to the He-alkaline earth pair potentials used in the calculations. The 5s5p <-- 5s2 transition of strontium atoms attached to helium nanodroplets of either isotope has been probed in absorption experiments. The spectra show that strontium is solvated inside 3He nanodroplets, supporting the calculations. In the light of our findings, we emphasize the relevance of the heavier alkaline earth atoms for analyzing mixed 3He-4He nanodroplets, and in particular, we suggest their use to experimentally probe the 3He-4He interface.
我们基于密度泛函计算给出了掺杂碱土原子的³He和⁴He纳米液滴的结构和能量学的系统结果。我们预测，从Mg到Ba的碱土原子会进入³He液滴的中心，而Ca、Sr和Ba位于⁴He液滴表面的一个深凹处，Mg则在其中心。对于Ca和Sr，计算中所使用的He - 碱土对势对凹处的结构显示出非常敏感的影响。在吸收实验中探测了附着在两种同位素的氦纳米液滴上的锶原子的5s5p ← 5s²跃迁。光谱表明锶在³He纳米液滴内部被溶剂化，这支持了计算结果。鉴于我们的发现，我们强调较重的碱土原子对于分析混合的³He - ⁴He纳米液滴的相关性，特别是，我们建议使用它们来通过实验探测³He - ⁴He界面。
