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We construct a new family of permutationally invariant codes that correct Pauli errors for any . We also show that codes in the new family correct quantum deletion errors as well as spontaneous decay errors. Our construction contains some of the previously known permutationally invariant quantum codes as particular cases, which also admit transversal gates. In many cases, the codes in the new family are shorter than the best previously known explicit permutationally invariant codes for Pauli errors and deletions. Furthermore, our new code family includes a new optimal single-deletion-correcting code. As a separate result, we generalize the conditions for permutationally invariant codes to correct Pauli errors from the previously known results for to any number of errors. For small , these conditions can be used to construct new examples of codes by computer.
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This content will become publicly available on October 18, 2026
Quasiclassical sampling and Wigner sampling of initial vibrational coordinates and momenta for polyatomic molecules in Monte Carlo molecular dynamics simulations
In a quasiclassical trajectory simulation, the vibrational modes are initialised with quantised vibrational energies, but vibrational phases are sampled by Monte Carlo. This requires an algorithm to assign coordinates and momenta to the various atoms. In this work, we present two methods for implementing this for nonrotating polyatomic molecules, namely, fixed-energy vibrational-state-selected initial conditions and thermal initial conditions. We also present a method for initiating classical trajectories with a ground-state Wigner distribution. These vibrational treatments are sufficient to initialise trajectories for unimolecular processes, and we also show how they can be applied to simulate bimolecular collision processes. The treatments of unimolecular and bimolecular collision processes are available in two Python codes called wigner_state_selected.py and bimolecular_collision.py, respectively, which will generate initial condition files that are recognisable by the SHARC and SHARC-MN computer programs for dynamics calculations. Both codes are available as standalone programs, as well as being included in SHARC-MN, and they will be included in future versions of SHARC. The methods implemented in these codes are mostly also available in the ANT computer program, and those that are not available in ANT will be incorporated in future versions of ANT.
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- Award ID(s):
- 2300321
- PAR ID:
- 10656259
- Publisher / Repository:
- Taylor & Francis Group
- Date Published:
- Journal Name:
- Molecular Physics
- Volume:
- 123
- Issue:
- 19-20
- ISSN:
- 0026-8976
- Subject(s) / Keyword(s):
- mass-weighted coordinates normal modes trajectories vibrational analysis Wigner distribution
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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