单元合集群用于在强磁场中的分子性质的量子计算
Tanner Culpitt1, Erik I Tellgren2, Fabijan Pavošević3
1Theoretical Chemistry Institute and Department of Chemistry, University of Wisconsin-Madison, 1101 University Ave., Madison, Wisconsin 53706, USA.
The Journal of chemical physics
|November 22, 2023
概括
单元合集群 (UCC) 方法,特别是单元合集群和双元合集群 (UCCSD),在强磁场中为化学系统提供可变的实值能量. 这种方法克服了标准合集群 (CC) 方法的局限性,该方法可以产生复杂的能量.
科学领域:
- 量子化学是一种量子化学.
- 计算化学是一种计算化学.
- 理论化学是一种理论化学.
背景情况:
- 截断合集群 (CC) 理论可以产生非变量和复杂的基态能量.
- 复杂的能量来自转换的哈密尔顿和CC截断的非赫密斯性质,特别是复杂的哈密尔顿,如在强磁场中的那些.
- 在磁场的存在下,对于精确的化学问题解决,实值的变量能量是可取的.
研究的目的:
- 将单元合集群 (UCC) 方法应用于受到强磁场影响的化学系统.
- 为了研究变量量子eigensolver算法与单元合集群单双 (UCCSD) 结合.
- 为了证明UCCSD对强磁场系统的标准CC方法的优势.
主要方法:
- 变量量子eigensolver算法的应用到单元合集群单双 (UCCSD) 方法.
- 在强磁场中对H2分子进行UCCSD的基准测试.
- 计算H4分子在各种几何形状和场角的UCCSD能量.
主要成果:
- 单元合集群单元和双元 (UCCSD) 始终产生变量和实值的能量.
- 标准合集群单体和双体 (CCSD) 可以产生复杂的能量,这些能量不是真实能量的上限.
- CCSD能源的虚构组件在强烈相关的区域中最为显著.
- 实际上,UCCSD计算有效地捕获了相对应能量的很大一部分.
结论:
- 单元合集群方法,特别是UCCSD,为在强磁场中获得可靠的能量提供了强大的解决方案.
- 在这些条件下,UCCSD保证了变化和实值能量,解决了传统CC方法的局限性.
- 该研究强调了UCCSD在涉及磁场的精确量子化学计算方面的潜力.
相关概念视频
00:59Atomic Nuclei: Nuclear Magnetic Moment
1.1K
All atomic nuclei are positively charged. When they have a nonzero spin, they behave like rotating charges. As a consequence of their charge and spin, these nuclei generate a magnetic field (B). This, in turn, gives rise to a magnetic moment (μ), which is randomly oriented in the absence of an external magnetic field. When an external magnetic field (B0) is applied, the magnetic moment vectors can align with the field or against it in 2 + 1 orientations. A hydrogen nucleus, which is just a...
1.1K
01:03Atomic Nuclei: Nuclear Spin State Overview
967
NMR-active nuclei have energy levels called 'spin states' that are associated with the orientations of their nuclear magnetic moments. In the absence of a magnetic field, the nuclear magnetic moments are randomly oriented, and the spin states are degenerate. When an external magnetic field is applied, the spin states have only 2 + 1 orientations available to them. A proton with = ½ has two available orientations. Similarly, for a quadrupolar nucleus with a nuclear spin value of...
967
01:23Atomic Nuclei: Nuclear Relaxation Processes
657
In the absence of an external magnetic field, nuclear spin states are degenerate and randomly oriented. When a magnetic field is applied, the spins begin to precess and orient themselves along (lower energy) or against (higher energy) the direction of the field. At equilibrium, a slight excess population of spins exists in the lower energy state. Because the direction of the magnetic field is fixed as the z-axis, the precessing magnetic moments are randomly oriented around the z-axis.
657
01:23Magnetic Field due to Moving Charges
8.7K
A stationary charge creates and interacts with the electric field, while a moving charge creates a magnetic field.
Consider a point charge moving with a constant velocity. Like the electric field, the magnetic field at any point is directly proportional to the magnitude of the charge and inversely proportional to the square of the distance between the source point and the field point. However, unlike the electric field, the magnetic field is always perpendicular to the plane containing the line...
Consider a point charge moving with a constant velocity. Like the electric field, the magnetic field at any point is directly proportional to the magnitude of the charge and inversely proportional to the square of the distance between the source point and the field point. However, unlike the electric field, the magnetic field is always perpendicular to the plane containing the line...
8.7K
02:58Crystal Field Theory - Octahedral Complexes
26.6K
Crystal Field Theory
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
26.6K
02:35Molecular Orbital Theory I
32.2K
Overview of Molecular Orbital Theory
32.2K