Corrigendum to “Trace preserving quantum dynamics using a novel reparametrization-neutral summation-by-parts difference operator” [J.Comput.Phys. 425 (2021) 109917](S0021999120306914)(10.1016/j.jcp.2020.109917)

Recently an error was discovered in the software implementation [1] of the trace preserving quantum Brownian motion evolution of a quarkonium particle, based on a reparameterization-neutral SBP operator, presented in [2]. This bug neither affects the preservation of the trace of the density matrix, nor does it change the survival probabilities for the particular parameters chosen in the original manuscript. I.e. the physics conclusions of the paper remain unchanged. However, after correction of the error, the conservation of the hermiticity of the density matrix was significantly improved, rendering deviations from exact hermiticity negligible as shown in Fig. 1. With the original code, deviations in hermiticity beyond floating point precision were observed, while with the corrected code a maximum imaginary part of the eigenvalues of the order of 10^-12 remains. Based on the combination of the reparameterization-neutral SBP operator [2] and the Crank–Nicolson scheme [3], we thus retain all defining continuum properties, unit trace and a real and positive spectrum, of the density matrix in the discrete setting. The authors would like to apologise for any inconvenience caused and thank Víctor López-Pardo (University of Santiago de Compostela) for spotting and correcting the error. An updated version [4] of the code has been posted to the Zenodo repository.