Zhenhao Duan^a,* and Haoran Sun^a

Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya, Hainan 572000, China

* Corresponding author. E-mail address: zduan@idsse.ac.cn

ABSTRACT

Presented herein is a novel online platform (https://efs.idsse.ac.cn/) that provides free access to the calculation of diverse thermodynamic properties of major gas fluid systems. The platform is built upon our decades-long body of work—encompassing equations of state published over the past thirty years and complementary computer simulations (e.g., Duan et al., 2025, 2026). These equations have been widely adopted across an array of research fields, including COH cycle modeling, carbon sequestration, fluid-rock interactions, fluid inclusion analysis, marine biogeochemistry, gas hydrate studies, and petroleum/gas geochemistry. As documented on the platform’s citation page (https://efs.idsse.ac.cn/module1/citation.html), the equations have earned endorsement or positive citation from 688 leading universities worldwide or institutions, involving contributions from over 10,000 scientists. Designed as a dynamic, continuously updated tool, this platform streamlines and simplifies geochemical computations, empowering researchers to execute critical thermodynamic analyses with enhanced efficiency.

(1)    Duan ZH, Cheng NF, Zhang ZG, Chou IM, Sun HR (2026) Molecular dynamics simulation and equation of state of the NaCl-H₂O system from 573 to 1573 K, 1 to 30 kbar, and 0 to 1 m fraction of NaCl. Geochimi. Cosmochimi. Acta. 412(2026) 127-141

(2)  Duan ZH and Cheng NF. （2025）Vapor-liquid and liquid-liquid phase equilibria in the CO₂-CH₄-N₂ system: A Gibbs ensemble Monte Carlo simulation. Chem. Geol. 693 (2025) 122983