相关实验视频
Updated: Jan 28, 2026

10:00
Gradient Echo Quantum Memory in Warm Atomic Vapor
Published on: November 11, 2013
13.2K
基底和激发状态梯度具有端到端可微分的半经验量子化学
Vishikh Athavale1, Maksim Kulichenko1, Nikita Fedik2
1Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
The Journal of chemical physics
|January 27, 2026
概括
自动分化 (AD) 为半经验量子化学提供了一个准确而高效的替代分析梯度. 这种方法与人工智能工作流程和流行的软件包无集成,为分子动力学模拟提供实用解决方案.
科学领域:
- 计算化学计算化学
- 量子化学 是一个量子化学.
- 材料科学 材料科学 材料科学
背景情况:
- 精确的分子能量梯度对于计算化学模拟至关重要,包括几何优化和分子动力学.
- 为新的电子结构方法推导分析梯度通常是复杂和劳动密集的.
研究的目的:
- 实施和评估基于分析,半数值和自动分化 (AD) 的梯度计算方法,用于半实证的哈密尔顿模型.
- 将这些梯度方法扩展到激发状态计算,使用配置相互作用单元和时间依赖的Hartree-Fock.
- 在各种分子系统上对这些方法的性能 (墙壁时间,内存使用,准确性) 进行基准测试.
主要方法:
- 在PYSEQM软件包中实现分析,半数字和AD梯度路径.
- 利用GPU和CPU架构来提高计算效率.
- 使用配置交互单元 (CIS) 和时间依赖的Hartree-Fock (TDHF) 扩展到激发状态.
- 在多种多样的分子家族中进行基准测试,高达1000个原子.
主要成果:
- 对于基本状态,分析和AD梯度显示了可比的GPU性能,而半数值方法在GPU上较慢,但在CPU上具有竞争力.
- 对于激发状态,分析和定制AD方法在内存使用量低的情况下提供类似的性能; 完全AD是内存密集型.
- 在所有测试系统中,AD梯度的准确性与分析梯度相匹配.
- 基于四子的旋转确保了两中心数量的光滑能量表面.
结论:
- 自动分化为半经验量子化学中的分析梯度提供了一个可行的和实用的替代方案.
- AD梯度促进了无集成到人工智能驱动的工作流和流行的计算包 (例如,PyTorch,JAX).
- 该研究为大规模分子动力学模拟选择最佳梯度策略提供了指导.
相关概念视频
Quantum Numbers
49.8K
It is said that the energy of an electron in an atom is quantized; that is, it can be equal only to certain specific values and can jump from one energy level to another but not transition smoothly or stay between these levels.
49.8K
The Quantum-Mechanical Model of an Atom
57.0K
Shortly after de Broglie published his ideas that the electron in a hydrogen atom could be better thought of as being a circular standing wave instead of a particle moving in quantized circular orbits, Erwin Schrödinger extended de Broglie’s work by deriving what is now known as the Schrödinger equation. When Schrödinger applied his equation to hydrogen-like atoms, he was able to reproduce Bohr’s expression for the energy and, thus, the Rydberg formula governing hydrogen spectra.
57.0K
What is an Electrochemical Gradient?
127.6K
Adenosine triphosphate, or ATP, is considered the primary energy source in cells. However, energy can also be stored in the electrochemical gradient of an ion across the plasma membrane, which is determined by two factors: its chemical and electrical gradients.
The chemical gradient relies on differences in the abundance of a substance on the outside versus the inside of a cell and flows from areas of high to low ion concentration. In contrast, the electrical gradient revolves around an...
The chemical gradient relies on differences in the abundance of a substance on the outside versus the inside of a cell and flows from areas of high to low ion concentration. In contrast, the electrical gradient revolves around an...
127.6K
Taping Over Different Ground Profiles
359
Taping over varying ground profiles requires careful adaptation to achieve accurate measurements. On smooth, level ground with minimal vegetation, the tape can rest directly on the ground. Here, the taping team, typically consisting of a head and a rear tapeman, coordinates their positions with clear communication. The rear tapeman holds the tape at the starting point and guides the head tapeman toward a range pole placed beyond the endpoint, using hand or voice signals to ensure alignment.On...
359
Chemistry of Carbohydrates
90.4K
Carbohydrates are an essential part of the diet in humans and animals. Grains, fruits, and vegetables are natural sources of carbohydrates that provide energy to the body, particularly through glucose, a simple sugar that is a component of starch and an ingredient in many staple foods. The stoichiometric formula (CH2O)n, where n is the number of carbons in the molecule represents carbohydrates. In other words, the ratio of carbon to hydrogen to oxygen is 1:2:1 in carbohydrate molecules. This...
90.4K
Chemistry of Carbohydrates
10.6K
10.6K

