Cc1ccc2nc(Nc3nc(O)cc(CSc4nc5ccccc5s4)n3)nc(C)c2c1
An acid's negative base-10 logarithmic dissociation constant (pKa) follows directly from its underlying thermodynamics; the negative pKa is directly proportional to its standard Gibbs free energy change. What is the negative pKa value of this molecule?