论文标题
完整配置互动（OptorBFCI）的最佳轨道选择：在预算下追求基集限制
Optimal Orbital Selection for Full Configuration Interaction (OptOrbFCI): Pursuing the Basis Set Limit under a Budget
论文作者
论文摘要
由于其昂贵的计算成本，完整的配置交互（FCI）求解器仅限于少量基集。提出了针对FCI（OptorBFCI）的最佳轨道选择，以增强现有FCI求解器在计算预算下追求基集限制的功能。优化问题与完整的Active Space SCF方法（CASSCF）相吻合，而OptorBFCI在算法上完全不同。 OptorBFCI通过直接求解受约束的优化问题有效地找到了最佳旋转矩阵，以压缩较大基集的轨道，该轨道仅在易于管理的尺寸上，仅在旋转的轨道集上进行FCI计算，并产生变异的基地能量及其波功能。结合坐标下降完整构型相互作用（CDFCI），我们证明了该方法在碳二聚体和氮二聚体基础基础上的效率和准确性设置为CC-PV5Z。我们还基准在CC-PVQZ基础下基准的氮二聚体的结合曲线具有28个选定的轨道，该轨道始终比CC-PVDZ基集下的FCI结果一致地提供地下态能。在这种情况下，解离能的准确性更高。
Full configuration interaction (FCI) solvers are limited to small basis sets due to their expensive computational costs. An optimal orbital selection for FCI (OptOrbFCI) is proposed to boost the power of existing FCI solvers to pursue the basis set limit under a computational budget. The optimization problem coincides with that of the complete active space SCF method (CASSCF), while OptOrbFCI is algorithmically quite different. OptOrbFCI effectively finds an optimal rotation matrix via solving a constrained optimization problem directly to compress the orbitals of large basis sets to one with a manageable size, conducts FCI calculations only on rotated orbital sets, and produces a variational ground-state energy and its wave function. Coupled with coordinate descent full configuration interaction (CDFCI), we demonstrate the efficiency and accuracy of the method on the carbon dimer and nitrogen dimer under basis sets up to cc-pV5Z. We also benchmark the binding curve of the nitrogen dimer under the cc-pVQZ basis set with 28 selected orbitals, which provide consistently lower ground-state energies than the FCI results under the cc-pVDZ basis set. The dissociation energy in this case is found to be of higher accuracy.
