Reactive transport softwares are today one of the cornerstones of environmental research. They contain multiphysics with very complex algorithms, including flow, transport, chemical, and sometimes heat transport, mechanical, and/or biological algorithms. Because of this complexity, some parts of these algorithms still have not been sufficiently studied. In this work, we focus on algorithms for activity correction, a specific subset of equilibrium chemistry algorithms. We show that the most used algorithm (the inner fixed-point algorithm) or the most rigorous algorithm (the full Newton) might not be the most efficient, and we propose a new one, the outer fixed-point algorithm, which is more robust and faster than other algorithms.

中文翻译：

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地球化学物种形成和反应输运建模的活动校正模型算法

反应传输软件是当今环境研究的基石之一。它们包含具有非常复杂算法的多物理场，包括流动、传输、化学，有时还有热传输、机械和/或生物算法。由于这种复杂性，这些算法的某些部分仍未得到充分研究。在这项工作中，我们专注于活性校正算法，这是平衡化学算法的一个特定子集。我们证明了最常用的算法（内定点算法）或最严格的算法（全牛顿）可能不是最有效的，我们提出了一种新算法，外定点算法，它更健壮并且比其他算法更快。