反应化学量子计算中的电子结构分类与态制备
Classification of electronic structures and state preparation for quantum computation of reaction chemistry
AI总结：
该研究针对反应化学量子计算的态制备难题，提出基于轨道纠缠的电子结构分类方案，明确两类多组态分子的特性，证明可借助低成本近似信息初始化反应化学的引导态。
摘要：
针对化学问题的量子计算需要构建与目标态具有足够重叠的引导态。由于易于获取且可初始化的平均场态的重叠度会随多组态电子结构而降低，甚至随系统规模增大而消失，我们在此研究了反应化学中态制备的严峻程度。我们强调了当前传统方法的弱点（即使对于弱相关分子也是如此），并突出了量子相位估计算法的优势。一项重要成果是提出了一种基于轨道纠缠信息的电子结构新分类方案。我们识别出两类多组态分子：第1类分子由极少的行列式主导，常见于反应化学中；第2类分子则无法筛选出数量合理的重要行列式。后者对传统方法来说尤其困难，是量子计算的终极目标，部分开壳铁硫簇属于第2类。我们讨论了分子轨道基组的作用，并表明真正的第2类分子无论选择何种轨道基组都保持该类别，固氮酶的铁钼辅因子就是典型例子。我们强调，第2类分子可以通过开壳中心或不饱和碳原子系统地构建。我们的核心结论是，基于初始的低成本近似电子结构信息，始终能够为基态下的化学反应化学初始化引导态，这得益于所考虑的原子结构的有限尺寸。
英文摘要：
Quantum computation for chemical problems will require the construction of guiding states with sufficient overlap with a target state. Since easily available and initializable mean-field states are characterized by an overlap that is reduced for multi-configurational electronic structures and even vanishes with growing system size, we here investigate the severity of state preparation for reaction chemistry. We emphasize weaknesses in current traditional approaches (even for weakly correlated molecules) and highlight the advantage of quantum phase estimation algorithms. An important result is the introduction of a new classification scheme for electronic structures based on orbital entanglement information. We identify two categories of multi-configurational molecules. Whereas class-1 molecules are dominated by very few determinants and often found in reaction chemistry, class-2 molecules do not allow one to single out a reasonably sized number of important determinants. The latter are particularly hard for traditional approaches and an ultimate target for quantum computation. Some open-shell iron-sulfur clusters belong to class 2. We discuss the role of the molecular orbital basis set and show that true class-2 molecules remain in this class independent of the choice of the orbital basis, with the iron-molybdenum cofactor of nitrogenase being a prototypical example. We stress that class-2 molecules can be build in a systematic fashion from open-shell centers or unsaturated carbon atoms. Our key result is that it will always be possible to initialize a guiding state for chemical reaction chemistry in the ground state based on initial low-cost approximate electronic structure information, which is facilitated by the finite size of the atomistic structures to be considered.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
