Conclusions
Combining the atom connection
relationship and group contribution method, atomic connectivity group
contribution (ACGC) method is proposed. Based on the relationship
between core atom and adjacent atoms, a new group defining method is
developed. To make the model more accurate, the shape factor is defined.
Atomic connectivity factors are defined to describe the position of each
group in a molecule based on the relationship between the core atom and
other non-hydrogen atoms. Together with the shape factors, most organic
isomers can be distinguished. The R 2 ofT c, P c andV c were 0.9891, 0.9887 and 0.9983, respectively.
The ARE of T c, P c andV c were 0.94%, 2.35% and 1.34 % respectively.
ARE of ACGC models with critical property are smaller than these of AAG
and AAGS, which shows that SF and ACF significantly improve the
performance of ACGC method. The ACGC model has high accuracy compared to
the classical GC model. From the above comparison, we can conclude that
ACGC method is accurate and reliable. We screened the data to ensure
that each group is present in more than five compounds. SF and ACF can
distinguish isomers effectively. Using the same formula, ACGC can
accurately calculate the critical properties of organic compounds, which
greatly facilitates the prediction and collection of properties of
undetectable organic compounds.