Interdimensional degeneracies in van der Waals clusters and quantum Monte Carlo computation of rovibrational states

D-dimensional energies for cesium and sodium dimers

We solve the Schrödinger equation with the improved Rosen−Morse potential energy model in D spatial dimensions. The D-dimensional rotation-vibrational energy spectra have been obtained by using the supersymmetric shape invariance approach. The energies for the 33[Formula: see text]g+ state of the Cs2 molecule and the 51Δg state of the Na2 molecule increase as D increases in the presence of fixed vibrational quantum number and various rotational quantum numbers. We observe that the change in behavior of the vibrational energies in higher dimensions remains similar to that of the three-dimensional system.

Vibrational Levels of Ar4: New Odd-Parity Bosonic States

Vibrational levels of Ar4 are computed using the Lanczos algorithm and a large basis set. We find both even- and odd-parity states with wave functions that are invariant with respect to permutations of the Ar atoms. The odd-parity bosonic levels have not been computed previously. The even-parity levels are close to those obtained using the correlation-function Monte Carlo method (CFMC).

Excited States of Weakly Bound Bosonic Clusters: Discrete Variable Representation and Quantum Monte Carlo

We compare two approaches for the accurate calculation of the energy levels of weakly bound boson trimers. The first approach is based on correlation function Monte Carlo employing optimized trial functions, while the second approach is based on the discrete variable representation. A trimer with atoms of half the mass of neon is used as a test problem for benchmark calculations. The two approaches yield identical results, within error bars, for all the J = 0 energy levels below the dissociation threshold. The relative merits of the two techniques are discussed, and a perspective is given for extension to larger clusters.