Verma Prakash, Huntington Lee, Coons Marc P, Kawashima Yukio, Yamazaki Takeshi, Zaribafiyan Arman
1QB Information Technologies (1QBit), 200-1285 W Pender St., Vancouver, British Columbia V6E 4B1, Canada.
Dow, Core R&D, Chemical Science, 1776 Building, Midland, Michigan 48674, USA.
J Chem Phys. 2021 Jul 21;155(3):034110. doi: 10.1063/5.0054647.
The method of increments and frozen natural orbital (MI-FNO) framework is introduced to help expedite the application of noisy, intermediate-scale quantum (NISQ) devices for quantum chemistry simulations. The MI-FNO framework provides a systematic reduction of the occupied and virtual orbital spaces for quantum chemistry simulations. The correlation energies of the resulting increments from the MI-FNO reduction can then be solved by various algorithms, including quantum algorithms such as the phase estimation algorithm and the variational quantum eigensolver (VQE). The unitary coupled-cluster singles and doubles VQE framework is used to obtain correlation energies for the case of small molecules (i.e., BeH, CH, NH, HO, and HF) using the cc-pVDZ basis set. The quantum resource requirements are estimated for a constrained geometry complex catalyst that is utilized in industrial settings for the polymerization of α-olefins. We show that the MI-FNO approach provides a significant reduction in the quantum bit (qubit) requirements relative to the full system simulations. We propose that the MI-FNO framework can create scalable examples of quantum chemistry problems that are appropriate for assessing the progress of NISQ devices.
引入增量与冻结自然轨道（MI-FNO）框架，以帮助加快噪声中等规模量子（NISQ）设备在量子化学模拟中的应用。MI-FNO框架为量子化学模拟提供了一种系统地减少占据轨道和虚拟轨道空间的方法。然后，可以通过各种算法求解MI-FNO约简产生的增量的相关能，包括量子算法，如相位估计算法和变分量子本征求解器（VQE）。使用酉耦合簇单双激发VQE框架，采用cc-pVDZ基组，计算小分子（即BeH、CH、NH、HO和HF）的相关能。估计了工业环境中用于α-烯烃聚合的受限几何结构复合催化剂的量子资源需求。我们表明，相对于全系统模拟，MI-FNO方法显著降低了量子比特（qubit）需求。我们提出，MI-FNO框架可以创建适用于评估NISQ设备进展的可扩展量子化学问题示例。
