Returns ΔG0 = -RT lnK for any recognised reaction at 25 °C. The calculator is based on the article
(New J. Chem., 2018, 42, 7617; DOI: 10.1039/c7nj03597g):

Use the general JESS format for reactions or the shortened method for formation reactions (when a species is formed just from its elements).

More powerful database interrogation programs are available when the JESS package is installed locally.