Open-system Renner–Teller dynamics with quantum Brownian motion within a Markovian Caldeira–Leggett limit

An open-system, coordinate-resolved formulation of Renner-Teller (RT) rovibronic dynamics is developed by embedding a two-state RT Hamiltonian in a quantum Brownian motion environment within the high-temperature, Markovian Caldeira-Leggett (CL) master-equation limit. I derive channel-resolved local balance laws for RT wavepacket densities in Jacobi coordinates, in which the Hermitian kinetic operator yields a curvilinear probability-current divergence, the RT off-diagonal blocks generate antisymmetric interchannel source-sink exchange, and the CL dissipator supplies coordinate-wise friction and momentum-diffusion corrections. These contributions are evaluated on a parity-adapted ΩK,M,ΛJ,p basis and used to construct a grid-resolved dominance analysis of the intersurface transfer-layer density for near-linear N2O. Application to the near-linear RT manifold of N2O illustrates how electronically controlled RT driving (through the adiabatic splitting ΔV and mixing angle α12) and bath-mediated dissipation jointly regulate the emergence, transport, reactivation, and late-time spreading of an intersurface transfer-layer density, providing a grid-resolved diagnostic that directly links wavepacket motion to environment-induced relaxation and decoherence.