Ab Initio Potential Energy Surface, Quantum Close-Coupling Scattering, and Transport Properties of the Au–N2 van der Waals Complex
- 1Computation-based Science and Technology Research Centre (CaSToRC
- 2Institute
Abstract
We present a first-principles characterization of the neutral Au–N 2 van der Waals complex, connecting ab initio electronic structure through quantum close-coupling scattering to macroscopic transport properties, bound rovibrational states, and the second virial coefficient. The two-dimensional rigid-rotor potential energy surface, computed at the UCCSD(T) level with a 60-electron effective core potential for Au, was obtained from a dense (R,θ) ab initio grid subjected to systematic outlier removal: a short-range (R ≲ 3–5 Å, angledependent) discontinuous branch, roughly two orders of magnitude deeper than the surrounding physical surface, was identified and excluded following diagnosis as a likely single-reference electronic-structure artifact, together with a smaller population of isolated numerical outliers. The resulting physical surface has a global well depth of −104.9 cm −1 , 1.5–3 times deeper than the isoelectronic neutral Ag–N 2 complex depending on orientation, consistent with gold’s larger polarizability and stronger relativistic effects. Full close-coupling scattering calculations show that Au–N 2 requires roughly twice the partial waves of Ag–N 2 to converge at equal collision energy, a direct, quantified consequence of the deeper well. Generalized Senftleben–Beenakker cross sections, computed at six collision energies spanning 20–500 cm −1 using a corrected channel-filtering procedure for energies at which some rotational levels are energetically closed, were thermally averaged via calibrated Chapman–Enskog theory to yield diffusion coefficients and viscosity for Au dilute in N 2 buffer gas. Twenty five converged bound rovibrational levels were located across three (J tot , parity) blocks, a richer progression than Ag–N 2 consistent with the deeper well, though the deepest few levels per block did not converge, a documented numerical limitation attributed to short-range potential extrapolation rather than a physical finding. The second virial coefficient remains negative throughout the tested range up to 1000 K, indicating a substantially higher Boyle temperature than neutral Ag–N 2 (370 K). Comparison with the isoelectronic Ag–N 2 system, and with prior close-coupling studies of the related Na–N 2 and Ag–N 2 systems, provides both physical-consistency checks and a quantitative picture of how relativistic and polarizability effects scale across this coinage-metal pair. To our knowledge, these constitute the first reported potential energy surface, scattering calculations, and transport properties for the Au–N 2 complex.
Related
- Quantifying light coupling to guided modes in semiconductor slabs with arbitrary scattering patterns
- Electronic transport in hBN-encapsulated graphene limited by remote phonon scattering
- Microfacet-based physics-driven framework for single-photon LiDAR rough-surface scattering and detection
- Nonuniform iterative phasing framework and sampling requirements for 3D dynamical inversion from coherent surface scattering imaging
- A Mesoscopic Ginzburg--Landau Model for Vibrational Strong Coupling Enhanced Rayleigh Scattering in Molecular Liquids
BibTeX
@misc{mohammadi2026initio,
title = {{Ab Initio Potential Energy Surface, Quantum Close-Coupling Scattering, and Transport Properties of the Au–N2 van der Waals Complex}},
author = {M. Doust Mohammadi and Mohsen Doust Mohammadi},
howpublished = {ChemRxiv},
year = {2026},
month = aug,
doi = {10.26434/chemrxiv.15008130/v1},
url = {https://chemrxiv.org/doi/full/10.26434/chemrxiv.15008130/v1},
note = {CC BY},
}
RIS
TY - UNPB
TI - Ab Initio Potential Energy Surface, Quantum Close-Coupling Scattering, and Transport Properties of the Au–N2 van der Waals Complex
AU - M. Doust Mohammadi
AU - Mohsen Doust Mohammadi
PY - 2026
DA - 2026/08/31
PB - ChemRxiv
DO - 10.26434/chemrxiv.15008130/v1
UR - https://chemrxiv.org/doi/full/10.26434/chemrxiv.15008130/v1
AB - We present a first-principles characterization of the neutral Au–N 2 van der Waals complex, connecting ab initio electronic structure through quantum close-coupling scattering to macroscopic transport properties, bound rovibrational states, and the second virial coefficient. The two-dimensional rigid-rotor potential energy surface, computed at the UCCSD(T) level with a 60-electron effective core potential for Au, was obtained from a dense (R,θ) ab initio grid subjected to systematic outlier removal: a short-range (R ≲ 3–5 Å, angledependent) discontinuous branch, roughly two orders of magnitude deeper than the surrounding physical surface, was identified and excluded following diagnosis as a likely single-reference electronic-structure artifact, together with a smaller population of isolated numerical outliers. The resulting physical surface has a global well depth of −104.9 cm −1 , 1.5–3 times deeper than the isoelectronic neutral Ag–N 2 complex depending on orientation, consistent with gold’s larger polarizability and stronger relativistic effects. Full close-coupling scattering calculations show that Au–N 2 requires roughly twice the partial waves of Ag–N 2 to converge at equal collision energy, a direct, quantified consequence of the deeper well. Generalized Senftleben–Beenakker cross sections, computed at six collision energies spanning 20–500 cm −1 using a corrected channel-filtering procedure for energies at which some rotational levels are energetically closed, were thermally averaged via calibrated Chapman–Enskog theory to yield diffusion coefficients and viscosity for Au dilute in N 2 buffer gas. Twenty five converged bound rovibrational levels were located across three (J tot , parity) blocks, a richer progression than Ag–N 2 consistent with the deeper well, though the deepest few levels per block did not converge, a documented numerical limitation attributed to short-range potential extrapolation rather than a physical finding. The second virial coefficient remains negative throughout the tested range up to 1000 K, indicating a substantially higher Boyle temperature than neutral Ag–N 2 (370 K). Comparison with the isoelectronic Ag–N 2 system, and with prior close-coupling studies of the related Na–N 2 and Ag–N 2 systems, provides both physical-consistency checks and a quantitative picture of how relativistic and polarizability effects scale across this coinage-metal pair. To our knowledge, these constitute the first reported potential energy surface, scattering calculations, and transport properties for the Au–N 2 complex.
ER -