arXivDaily arXiv每日学术速递 周一至周五更新
arXiv周末暂无论文更新,休息一下吧,周末愉快~~
arXiv 1908.00971physics.chem-phphysics.comp-ph
收藏

物理机器学习在量子化学中胜过“人类学习”

Physical machine learning outperforms "human learning" in Quantum Chemistry

Anton V. Sinitskiy, Vijay S. Pande

摘要:

两种类型的方法来模拟分子系统已被证明具有很高的实用效率。密度泛函理论(DFT)是一种预测分子能量和电子密度的物理方法,是应用最广泛的量子化学方法。最近,许多关于分子性质的机器学习(ML)的论文也已发表。ML模型在计算成本方面大大优于DFT,甚至可能达到相当的精度,但它们缺少物理性-与量子物理学的直接联系-这限制了它们的适用性。在这里,我们提出了一种方法,结合了DFT和ML的强侧,即物理性和低计算成本。通过推广著名的Hohenberg-Kohn定理,我们导出了精确电子密度和能量的一般方程,这些方程可以自然地指导ML在量子化学中的应用。基于这些方程,我们构建了一个深度神经网络,它可以计算各种有机分子的电子密度和能量,不仅速度更快,而且比当前版本的DFT更接近精确的物理值。特别是,我们达到了一个平均绝对误差的能量与多达8个非氢原子低至0.9千卡/摩尔相对于CCSD(T)值,明显低于DFT(低至~3千卡/摩尔的同一组分子)和ML(低至~1.5千卡/摩尔)的方法。电子密度和能量的预测精度的同时提高表明,所提出的方法描述的物理分子比DFT泛函开发的“人类学习”更早。因此,基于物理学的机器学习提供了令人兴奋的机会,可以以高理论水平的量子化学准确性对比目前可能的更大的分子系统进行建模。

英文摘要:

Two types of approaches to modeling molecular systems have demonstrated high practical efficiency. Density functional theory (DFT), the most widely used quantum chemical method, is a physical approach predicting energies and electron densities of molecules. Recently, numerous papers on machine learning (ML) of molecular properties have also been published. ML models greatly outperform DFT in terms of computational costs, and may even reach comparable accuracy, but they are missing physicality - a direct link to Quantum Physics - which limits their applicability. Here, we propose an approach that combines the strong sides of DFT and ML, namely, physicality and low computational cost. By generalizing the famous Hohenberg-Kohn theorems, we derive general equations for exact electron densities and energies that can naturally guide applications of ML in Quantum Chemistry. Based on these equations, we build a deep neural network that can compute electron densities and energies of a wide range of organic molecules not only much faster, but also closer to exact physical values than current versions of DFT. In particular, we reached a mean absolute error in energies of molecules with up to eight non-hydrogen atoms as low as 0.9 kcal/mol relative to CCSD(T) values, noticeably lower than those of DFT (down to ~3 kcal/mol on the same set of molecules) and ML (down to ~1.5 kcal/mol) methods. A simultaneous improvement in the accuracy of predictions of electron densities and energies suggests that the proposed approach describes the physics of molecules better than DFT functionals developed by "human learning" earlier. Thus, physics-based ML offers exciting opportunities for modeling, with high-theory-level quantum chemical accuracy, of much larger molecular systems than currently possible.

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。

↑