Multichannel quantum defect theory for cold molecular collisions

Croft, James; Wallis, Alisdair O. G.; Hutson, Jeremy M.; Julienne, Paul S.

doi:10.1103/physreva.84.042703

Cited by 41 publications

(57 citation statements)

References 63 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[13], using the renormalized Numerov method [25] to solve the onedimension Schrödinger equations for the reference potentials. The MQDT Y matrix was then obtained by matching to the log-derivative matrix extracted from the coupled-channel propagation at a distance r match .…”

Section: B Numerical Methodsmentioning

confidence: 99%

“…This is the same system as considered in Ref. [13], but the present work uses a larger 022711-2 basis set, which introduces more scattering resonances and denser poles in the Y matrix.…”

Section: A Basis Sets and Quantum Numbersmentioning

confidence: 99%

“…We give here only a brief description, following Ref. [13], which is sufficient to describe the notation we use.…”

Section: Theorymentioning

confidence: 99%

“…In our approach [13], Y is obtained numerically by matching the solutions of the coupled-channel equations to f i (r) and g i (r) at r match . The S matrix is then obtained from Y using Eqs.…”

Section: Theorymentioning

confidence: 99%

“…We have recently shown [13] that multichannel quantum defect theory (MQDT) [14][15][16][17][18][19] provides an attractive alternative to full coupled-channel calculations in these circumstances. MQDT attempts to represent the scattering properties in terms of a matrix Y (E,B) [16][17][18][19] that is a smooth function of E and B.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Optimized multichannel quantum defect theory for cold molecular collisions

2012

Self Cite

View full text Add to dashboard Cite

Use policyThe full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-pro t purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details. Multichannel quantum defect theory (MQDT) can provide an efficient alternative to full coupled-channel calculations for low-energy molecular collisions. However, the efficiency relies on interpolation of the Y matrix that encapsulates the short-range dynamics, and there are poles in Y that may prevent interpolation over the range of energies of interest for cold molecular collisions. We show how the phases of the MQDT reference functions may be chosen so as to remove such poles from the vicinity of a reference energy and dramatically increase the range of interpolation. For the test case of Mg + NH, the resulting optimized Y matrix may be interpolated smoothly over an energy range of several Kelvin and a magnetic field range of over 1000 gauss. Calculations at additional energies and fields can then be performed at a computational cost that is proportional to the number of channels N and not to N 3 .

show abstract

Section: B Numerical Methodsmentioning

confidence: 99%

“…This is the same system as considered in Ref. [13], but the present work uses a larger 022711-2 basis set, which introduces more scattering resonances and denser poles in the Y matrix.…”

Section: A Basis Sets and Quantum Numbersmentioning

confidence: 99%

“…We give here only a brief description, following Ref. [13], which is sufficient to describe the notation we use.…”

Section: Theorymentioning

confidence: 99%

Section: Theorymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Optimized multichannel quantum defect theory for cold molecular collisions

2012

Self Cite

View full text Add to dashboard Cite

show abstract

Experimental and Theoretical Studies of Low‐Energy Penning Ionization of NH₃, CH₃F, and CHF₃

et al. 2016

View full text Add to dashboard Cite

We present results from a joint theoretical and experimental study of the low-energy Penning ionization of NH , CH F, and CHF by metastable Ne( P ) and He( S ) atoms. We combine the merged neutral beams experiment, covering a range of collision energies between 0.1-150 K, with multichannel quantum defect theory calculations based on interaction potentials from symmetry-adapted perturbation theory. The three symmetric tops provide several distinct properties that make them interesting targets for cold chemistry studies. Of these three, only NH has a lone electron pair that leads to a strong binding with rare gas atoms. The CHF molecule has much smaller rotational constants than both NH and CH F, and thus has a considerably higher density of rotational states already at low energies. Their presence opens inelastic collision channels that reduce the observed reactive cross section. We show that this effect dominates the total rate coefficient in heavy molecules already at relatively low collision energies but is much less prominent for lighter molecules.

show abstract

Potential energy surface and bound states of the (X⁴Σ)KRb‐K complex

López‐Durán

Aguirre

Delgado‐Barrio

et al. 2014

Int J of Quantum Chemistry

View full text Add to dashboard Cite

We present in this work a potential energy surface of the (X4Σ)KRb‐K complex for which high level ab initio calculations have been carried out at the RCCSD(T) level of theory, using ECP10MDF/ECP28MDF effective core potentials and basis sets for K/Rb, respectively, with the dimer at its lowest triplet 3Σ state and fixed to the equilibrium distance. The interaction is shown to be very anisotropic, with one clear minimum at a T‐type geometry of the complex. The depth of the well is found to be 767.7 cm−1 located at R=4.60 Å,θ=105° in Jacobi coordinates from the center of mass of the diatomic partner. A variational (VAR) procedure and the Diffusion Monte Carlo technique have been applied to explore the bound states of the aggregate. Both descriptions provide similar features for the vibrational, nonrotating, ground‐state, with an energy of ∼−737.8 cm−1 and the maximum of the wavefunction peaked above the well of the surface. Excited states are also reported using the VAR treatment and angular and/or radial excitations are identified among the lower‐lying vibrational states. These results should already provide an initial step toward a more comprehensive study of the collisions at ultralow temperatures of K+KRb, important process in the field of ultracold molecular chemistry. © 2014 Wiley Periodicals, Inc.

show abstract

Multichannel quantum defect theory for cold molecular collisions

Cited by 41 publications

References 63 publications

Optimized multichannel quantum defect theory for cold molecular collisions

Optimized multichannel quantum defect theory for cold molecular collisions

Experimental and Theoretical Studies of Low‐Energy Penning Ionization of NH₃, CH₃F, and CHF₃

Potential energy surface and bound states of the (X⁴Σ)KRb‐K complex

Contact Info

Product

Resources

About

Multichannel quantum defect theory for cold molecular collisions

Cited by 41 publications

References 63 publications

Optimized multichannel quantum defect theory for cold molecular collisions

Optimized multichannel quantum defect theory for cold molecular collisions

Experimental and Theoretical Studies of Low‐Energy Penning Ionization of NH3, CH3F, and CHF3

Potential energy surface and bound states of the (X4Σ)KRb‐K complex

Contact Info

Product

Resources

About

Experimental and Theoretical Studies of Low‐Energy Penning Ionization of NH₃, CH₃F, and CHF₃

Potential energy surface and bound states of the (X⁴Σ)KRb‐K complex