Uncoordinated nitrogen, as defined in this study, refers to nitrogen atoms that are not part of metal coordination complexes or azole linkers, such as those in amine groups or azines. They have been experimentally recognized as promising functional groups for DAC applications. The lone pair on nitrogen atom create localized pockets within the framework that act as nucleophilic site, facilitating strong interactions with electrophilic CO2 molecules. Consequently, 87.5 % of MOFs containing uncoordinated nitrogen exhibit CO2 Qst values exceeding 58.9 kJ/mol (the top 25 % CO2 Qst value of the candidates) and selectivity greater than 100. Notably, selective CO2 capture associated with amine groups occurs generally via chemical reaction, highlighting the need for further research to fully understand this selective behavior.