MOLSCAT: a program for non-reactive quantum scattering calculations on atomic and molecular collisions

Abstract

MOLSCAT is a general-purpose program for quantum-mechanical calculations on nonreactive atom-atom, atom-molecule and molecule-molecule collisions. It constructs the coupled-channel equations of atomic and molecular scattering theory, and solves them by propagating the wavefunction or log-derivative matrix outwards from short range to the asymptotic region. It then applies scattering boundary conditions to extract the scattering matrix (S matrix). Built-in coupling cases include atom + rigid linear molecule, atom + vibrating diatom, atom + rigid symmetric top, atom + asymmetric or spherical top, rigid diatom + rigid diatom, rigid diatom + asymmetric top, and diffractive scattering of an atom from a crystal surface. Interaction potentials may be specified either in program input (for simple cases) or with user-supplied routines. For the built-in coupling cases, MOLSCAT can loop over partial wave (or total angular momentum) to calculate elastic and inelastic cross integral sections and spectroscopic line-shape cross sections. Post-processors are available to calculate differential cross sections, transport, relaxation and Senftleben-Beenakker cross sections, and to fit the parameters of scattering resonances. MOLSCAT also provides an interface for plug-in routines to specify coupling cases (Hamiltonians and basis sets) that are not built in; plug-in routines are supplied to handle collisions of a pair of alkali-metal atoms with hyperfine structure in an applied magnetic field. For low-energy scattering, MOLSCAT can calculate scattering lengths and effective ranges and can locate and characterize scattering resonances as a function of an external variable such as the magnetic field.

arXiv commentarXiv admin note: substantial text overlap with arXiv:1811.09111 This is because these are two parallel papers that describe related programs with the same theoretical basis but for different purposes

References in corpus (11)

• Hyperfine, rotational, and vibrational structure of the triplet ground state of Rb molecules
• Feshbach resonances in ultracold atomic and molecular collisions: threshold behaviour and suppression of poles in scattering lengths
• Production of ultracold NH molecules by sympathetic cooling with Mg
• Ultracold atom-molecule collisions and bound states in magnetic fields: tuning zero-energy Feshbach resonances in He-NH (3Sigma-)
• Avoided crossings between bound states of ultracold Cesium dimers
• Multichannel Quantum Defect Theory for cold molecular collisions
• BOUND and FIELD: programs for calculating bound states of interacting pairs of atoms and molecules
• Prospects for sympathetic cooling of polar molecules: NH with alkali-metal and alkaline-earth atoms - a new hope
• Effective-range approximations for resonant scattering of cold atoms
• Characterizing Feshbach resonances in ultracold scattering calculations
• Optimized Multichannel Quantum Defect Theory for cold molecular collisions

Cited by in corpus (45)

• Lee-Huang-Yang effects in the ultracold mixture of ${}^{23}$Na and ${}^{87}$Rb with attractive interspecies interactions
• Forming a single molecule by magnetoassociation in an optical tweezer
• Precision Test of the Limits to Universality in Few-Body Physics
• BOUND and FIELD: programs for calculating bound states of interacting pairs of atoms and molecules
• Observation of Efimov Universality across a Non-Universal Feshbach Resonance in \textsuperscript{39}K
• Pinpointing Feshbach Resonances and Testing Efimov Universalities in ${}^{39}$K
• Preparation of one ${}^{87}$Rb and one ${}^{133}$Cs atom in a single optical tweezer
• Coherent optical creation of a single molecule
• Probing open- and closed-channel p-wave resonances
• Dynamics on Multiple Potential Energy Surfaces: Quantitative Studies of Elementary Processes Relevant to Hypersonics
• Magnetic Feshbach resonances in ultracold collisions between Cs and Yb atoms
• Improved characterization of Feshbach resonances and interaction potentials between ${}^{23}$Na and ${}^{87}$Rb atoms
• Benchmarking an improved statistical adiabatic channel model for competing inelastic and reactive processes
• Collisional excitation of methyl (iso)cyanide by He atoms: rate coefficients and isomerism effects
• Characterizing quasibound states and scattering resonances
• Prospects of forming high-spin polar molecules from ultracold atoms
• Quantum chaos in Feshbach resonances of the ErYb system
• Ultracold collisions of Cs in excited hyperfine and Zeeman states
• Ab initio quantum dynamics as a scalable solution to the exoplanet opacity challenge: A case study of CO${}_2$ in hydrogen atmosphere
• Interaction potential for NaCs for ultracold scattering and spectroscopy
• Feshbach Spectroscopy of Cs Atom Pairs in Optical Tweezers
• Quantum control of ion-atom collisions beyond the ultracold regime
• Feshbach resonances and molecule formation in ultracold mixtures of Rb and Yb(${}^3$P) atoms
• First close-coupling study of the excitation of a large cyclic molecule: collision of c-C5H6 with He
• Time delays in ultracold atomic and molecular collisions
• Inelastic collisions in radiofrequency-dressed mixtures of ultracold atoms
• Rate Coefficients for Rotational State-to-State Transitions in H${}_2$O + H${}_2$ Collisions as Predicted by Mixed Quantum/Classical Theory (MQCT)
• Dynamics of translational and rotational thermalization of AlF molecules via collisions with cryogenic helium
• Temperature-dependent rotationally inelastic collisions of OH- and He
• On Mixed Quantum/Classical Theory for Rotationally Inelastic Scattering of Identical Collision Partners
• Feshbach resonances in an ultracold ${}^7$Li-${}^{133}$Cs Bose-Bose mixture
• Multichannel quantum defect theory with a frame transformation for ultracold atom-molecule collisions in magnetic fields
• Probing the interaction energy of two ${}^{85}$Rb atoms in an optical tweezer via spin-motion coupling
• Numerical evaluation of orientation averages and its application to molecular physics
• Spin--spin interaction and magnetic Feshbach resonances in collisions of high-spin atoms with closed-shell atoms
• Magnetic Feshbach resonances between atoms in ${}^2$S and ${}^3$P${}_0$ states: mechanisms and dependence on atomic properties
• Rotational excitation cross sections for chloronium based on a new 5D interaction potential with molecular hydrogen
• Formation of ultracold ${}^{39}$K${}^{133}$Cs Feshbach molecules
• Revealing Energy Dependence of Quantum Defects via Two Heteronuclear Atoms in an Optical Tweezer
• Dimer-projection contact and the clock shift of a unitary Fermi gas
• Characterization of Feshbach resonances in ${}^6\mathrm{Li}{-}^7\mathrm{Li}$ using improved interaction potentials
• Interactions and cold collisions of AlF in the ground and excited electronic states with He
• Neural network ensemble for computing cross sections for rotational transitions in H${}_2$O + H${}_2$O collisions
• Factor of 1000 suppression of the depolarization rate in ultracold thulium collisions
• Low-temperature scattering with the R-matrix method: from nuclear scattering to atom-atom scattering and beyond