One of the most commonly used molecular inputs for ionic
liquids
and deep eutectic solvents (DESs) in the literature are the critical
properties and acentric factors, which can be easily determined using
the modified Lydersen–Joback–Reid (LJR) method with
Lee–Kesler mixing rules. However, the method used in the literature
is generally applicable only to binary mixtures of DESs. Nevertheless,
ternary DESs are considered to be more interesting and may provide
further tailorability for developing task-specific DESs for particular
applications. Therefore, in this work, a new framework for estimating
the critical properties and the acentric factor of ternary DESs based
on their molecular structures is presented by adjusting the framework
reported in the literature with an extended version of the Lee–Kesler
mixing rules. The presented framework was applied to a data set consisting
of 87 ternary DESs with 334 distinct compositions. For validation,
the estimated critical properties and acentric factors were used to
predict the densities of the ternary DESs. The results showed excellent
agreement between the experimental and calculated data, with an average
absolute relative deviation (AARD) of 5.203% for ternary DESs and
5.712% for 260 binary DESs (573 compositions). The developed methodology
was incorporated into a user-friendly Excel worksheet for computing
the critical properties and acentric factors of any ternary or binary
DES, which is provided in the Supporting Information. This work promotes
the creation of robust, accessible, and user-friendly models capable
of predicting the properties of new ternary DESs based on critical
properties, thus saving time and resources.