Weight Braden M, Mandal Arkajit, Hu Deping, Huo Pengfei
Department of Physics and Astronomy, University of Rochester, Rochester, New York 14627, USA.
Department of Chemistry, Texas A&M University, College Station, Texas 77842, USA.
J Chem Phys. 2025 Feb 28;162(8). doi: 10.1063/5.0248950.
We perform on-the-fly non-adiabatic molecular dynamics simulations using the recently developed spin-mapping formalism. Two quantum dynamics approaches based on this mapping formalism, (i) the fully linearized Spin-LSC and (ii) the partially linearized Spin-PLDM, are explored using the quasi-diabatic propagation scheme. We have performed dynamics simulations in four ab initio molecular models for which benchmark ab initio multiple spawning (AIMS) data have been published. We find that the spin-LSC and the previously reported symmetric quasi-classical (SQC) approaches provide nearly equivalent population dynamics. While we expected the more involved spin-PLDM method to provide superior accuracy compared to the other mapping-based approaches, SQC and spin-LSC, we found that it performed with equivalent accuracy compared to the AIMS benchmark results. We further explore the underpinnings of the spin-PLDM correlation function by decomposing its N2 density matrix-focused initial conditions, where N is the number of states in the quantum subsystem. Finally, we found an approximate form of the spin-PLDM correlation function, which simplifies the simulation and reduces the computational costs from N2 to N.
我们使用最近开发的自旋映射形式体系进行实时非绝热分子动力学模拟。基于这种映射形式体系的两种量子动力学方法，即（i）完全线性化的自旋 - LSC和（ii）部分线性化的自旋 - PLDM，采用准绝热传播方案进行了探索。我们在四个从头算分子模型中进行了动力学模拟，针对这些模型已经发表了基准从头算多重生成（AIMS）数据。我们发现自旋 - LSC和先前报道的对称准经典（SQC）方法提供了几乎等效的布居动力学。虽然我们预期更复杂的自旋 - PLDM方法与其他基于映射的方法（SQC和自旋 - LSC）相比能提供更高的精度，但我们发现它与AIMS基准结果相比具有同等的精度。我们通过分解其以N2密度矩阵为重点的初始条件（其中N是量子子系统中的状态数），进一步探索了自旋 - PLDM相关函数的基础。最后，我们找到了自旋 - PLDM相关函数的一种近似形式，它简化了模拟并将计算成本从N2降低到了N。
