



@article {2585,
	title = {Collisions of room-temperature helium with ultracold lithium and the van der Waals bound state of HeLi},
	journal = {Phys. Rev. A },
	volume = {101},
	year = {2020},
	month = {1/6/2020},
	abstract = {<p>We have computed the thermally averaged total, elastic rate coefficient for the collision of a room-temperature helium atom with an ultracold lithium atom. This rate coefficient has been computed as part of the characterization of a cold-atom vacuum sensor based on laser-cooled Li 6 or Li 7 atoms that will operate in the ultrahigh-vacuum (p\&lt; 10\&minus; 6 Pa) and extreme-high-vacuum (p\&lt; 10\&minus; 10 Pa) regimes. The analysis involves computing the X 2 Σ+ HeLi Born-Oppenheimer potential followed by the numerical solution of the relevant radial Schr{\"o}dinger equation. The potential is computed using a single-reference-coupled-cluster electronic-structure method with basis sets of different completeness in order to characterize our uncertainty budget. We predict that the rate coefficient for a 300 K helium gas and a 1 μ K Li gas is 1.467 (13)\&times; 10\&minus; 9 cm 3/s for He 4+ Li 6 and 1.471 (13)\&times; 10\&minus; 9 cm 3/s for He 4+ Li 7, where the \&hellip;</p>},
	doi = {https://doi.org/10.1103/PhysRevA.101.012702},
	author = {Constantinos Makrides and Daniel S Barker and James A Fedchak and Julia Scherschligt and Stephen Eckel and Eite Tiesinga}
}
