*3.9. Complexes with Amino Acids–Energy Partitioning with SSMF and F-SAPT*

The energy partitioning in the SMF approaches is a byproduct of the SMF procedure and sometimes two interesting groups are placed in the same fragments, and thus, impossible to separate. However, in many other cases, they are sometimes attributed to different fragments, and then by the elimination analysis one can establish which molecular group in a given molecule is responsible for the highest interaction strength. The systematic way of performing such an analysis consists in a selection of those interaction energies between the calixarene fragment and the amino acid (see Equation (3)), which have the highest absolute values, and the following investigation of how the removal or addition of a neighboring unit influences the interaction energy with the amino acid.
