Related papers: Cold and ultracold NH--NH collisions: The field-fr…
Elastic and spin-changing inelastic collision cross sections are presented for cold and ultracold magnetically trapped NH. The cross sections are obtained from coupled-channel scattering calculations as a function of energy and magnetic…
We calculate the quartet potential energy surface for Li+NH and use it to calculate elastic and spin-relaxation cross sections for collisions in magnetically trappable spin-stretched states. The potential is strongly anisotropic but…
We investigate the effect of hyperfine interactions on ultracold molecular collisions in magnetic fields, using ^{24}Mg(^1S) + ^{14}NH(^3Sigma^-) as a prototype system. We explore the energy and magnetic field dependence of the cross…
We calculate the interaction potential between N atoms and NH molecules and use it to investigate cold and ultracold collisions important for sympathetic cooling. The ratio of elastic to inelastic cross sections is large over a wide range…
We have calculated elastic and state-resolved inelastic cross sections for cold and ultracold collisions in the Rb($^1 S$) + OH($^2 \Pi_{3/2}$) system, including fine-structure and hyperfine effects. We have developed a new set of five…
We carry out quantum inelastic scattering calculations of collisions of Rb atoms with inverting NH3 and ND3 molecules in the energy range between 0 and 100 cm-1, which are important for experiments using velocity-controlled molecular beams…
We investigate the ultracold reaction dynamics of magnetically trapped NH($X ^3\Sigma^-$) radicals using rigorous quantum scattering calculations involving three coupled potential energy surfaces. We find that the reactive NH + NH cross…
We carry out calculations on $M$-changing collisions of NH ($^3\Sigma^-$) molecules in magnetically trappable states using a recently calculated potential energy surface. We show that elastic collision rates are much faster than inelastic…
Collision cross sections and rate constants between two ground- state oxygen molecules are investigated theoretically at translational energies below $\sim 1$K and in zero magnetic field. We present calculations for elastic and spin-…
We present a detailed analysis of the role of the magnetic dipole-dipole interaction in cold and ultracold collisions. We focus on collisions between magnetically trapped NH molecules, but the theory is general for any two paramagnetic…
Scattering and ionizing cross sections and rates are calculated for ultracold collisions between metastable helium atoms using a fully quantum-mechanical close-coupled formalism. Homonuclear collisions of the bosonic ${}^{4}$He$^{*}…
We present a treatment of cold hydrogen-antihydrogen collisions based on the asymptotic properties of atom-antiatom interactions. We derive general formulas for the elastic and inelastic cross sections and for the scattering lengths and…
We report elastic and inelastic cross sections for fast superthermal $^{12}$C($^3P$) and $^{13}$C($^3P$) atoms scattering on $^{12}$CO$_2$. The cross sections were computed using quantum-mechanical rotationally close-coupling formalism with…
We theoretically study slow collisions of NH$_3$ molecules with He atoms, where we focus in particular on the observation of scattering resonances. We calculate state-to-state integral and differential cross sections for collision energies…
A potential energy surface for the lowest quartet electronic state of lithium trimer is developed and used to study spin-polarized Li + Li_2 collisions at ultralow kinetic energies. The potential energy surface allows barrierless atom…
We show that low-energy inelastic cross sections can decrease as well as increase in the vicinity of a zero-energy Feshbach resonance. When an external field is used to tune across such a resonance, the real and imaginary parts of the…
We show theoretically that ultracold hydrogen atoms have very favorable properties for sympathetic cooling of molecules to microkelvin temperatures. We calculate the potential energy surfaces for spin-polarized interactions of H atoms with…
We show that the cross sections for a broad range of resonant {\it inelastic} processes accompanied by excitation exchange (such as spin-exchange, F\"orster resonant, or angular momentum exchange) exhibit an unconventional near-threshold…
We have generalized the BOUND and MOLSCAT packages to allow calculations in basis sets where the monomer Hamiltonians are off-diagonal and used the new capability to carry out bound-state and scattering calculations on 3He-NH and 4He-NH as…
The collision dynamics of $^{17}O_2(^3\Sigma_g^-) +^{17}O_2(^3\Sigma_g^-)$ in the presence of a magnetic field is studied within the close-coupling formalism in the range between 10 nK and 50 mK. A recent global {\em ab initio} potential…