BOUND and FIELD: programs for calculating bound states of interacting pairs of atoms and molecules

Abstract

The BOUND program calculates the bound states of a complex formed from two interacting particles using coupled-channel methods. It is particularly suitable for the bound states of atom-molecule and molecule-molecule Van der Waals complexes and for the near-threshold bound states that are important in ultracold physics. It uses a basis set for all degrees of freedom except $R$, the separation of the centres of mass of the two particles. The Schrödinger equation is expressed as a set of coupled equations in $R$. Solutions of the coupled equations are propagated outwards from the classically forbidden region at short range and inwards from the classically forbidden region at long range, and matched at a point in the central region. 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, and rigid diatom + asymmetric top. Both programs provide an interface for plug-in routines to specify coupling cases (Hamiltonians and basis sets) that are not built in. With appropriate plug-in routines, BOUND can take account of the effects of external electric, magnetic and electromagnetic fields, locating bound-state energies at fixed values of the fields. The related program FIELD uses the same plug-in routines and locates values of the fields where bound states exist at a specified energy. As a special case, it can locate values of the external field where bound states cross scattering thresholds and produce zero-energy Feshbach resonances. Plug-in routines are supplied to handle the bound states of a pair of alkali-metal atoms with hyperfine structure in an applied magnetic field.

One of two parallel papers that document the MOLSCAT, BOUND and FIELD programs, which use closely related theoretical methods but serve different purposes. This paper and arXiv:1811.09584 therefore have substantial text overlap

References in corpus (5)

• MOLSCAT: a program for non-reactive quantum scattering calculations on atomic and molecular collisions
• Hyperfine, rotational, and vibrational structure of the triplet ground state of Rb molecules
• 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
• Near-threshold bound states of the dipole-dipole interaction

Cited by in corpus (23)

• MOLSCAT: a program for non-reactive quantum scattering calculations on atomic and molecular collisions
• Forming a single molecule by magnetoassociation in an optical tweezer
• Formation of ultracold molecules by merging optical tweezers
• Observation of the Hanbury Brown and Twiss Effect with Ultracold Molecules
• Coherent optical creation of a single molecule
• Probing open- and closed-channel p-wave resonances
• 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
• An improved study of HCO+ and He system: interaction potential, collisional relaxation and pressure broadening
• 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
• Interaction potential for NaCs for ultracold scattering and spectroscopy
• Magnetic Feshbach resonances in ultracold atom-molecule collisions
• Feshbach resonances and molecule formation in ultracold mixtures of Rb and Yb(${}^3$P) atoms
• Time delays in ultracold atomic and molecular collisions
• Feshbach resonances in an ultracold ${}^7$Li-${}^{133}$Cs Bose-Bose mixture
• Magnetic Feshbach resonances between atoms in ${}^2$S and ${}^3$P${}_0$ states: mechanisms and dependence on atomic properties
• Spin--spin interaction and magnetic Feshbach resonances in collisions of high-spin atoms with closed-shell atoms
• Dimer-projection contact and the clock shift of a unitary Fermi gas
• Formation of ultracold ${}^{39}$K${}^{133}$Cs Feshbach molecules
• Interactions and cold collisions of AlF in the ground and excited electronic states with He
• Characterization of Feshbach resonances in ${}^6\mathrm{Li}{-}^7\mathrm{Li}$ using improved interaction potentials