Finally, Gaussian16 74 is used for the semiempirical PM6 99 and PM7 100 methods with the Berny optimizer 101 and default convergence criteria. The same is true for the B3LYP/6-31G(d,p) reference calculations with the differ-ence that very tight (tight) convergence criteria with ultrafine grid were chosen for GPGG (gramicidin). The performance of all these alternative surrogates compared to the B3LYP/6-31G(d,p) reference are discussed in the next section.