*4.5. Software*

Gaussian 09 [59] and 16 [60] produced optimized structures and the extrapolation sequence of RHF, MP2, and coupled-cluster energies. Atoms-in-Molecules results were obtained with AIMALL [61]. NCIPLOT was obtained by download from the Contreras-Garcia group [62] and LMODEA software for the local modes analysis [63] was provided by the Kraka group.

**Supplementary Materials:** The following are available online, which includes: Electronic energies used in extrapolation; Cartesian coordinates of all species; AIM figures with bond paths, line critical points and associated values of the Laplacian of the electron density.

**Author Contributions:** Conceptualization, C.T. and Z.A.; methodology, C.T.; software, Z.A. and E.A.B.; validation, C.T., Z.A. and E.A.B.; formal analysis, C.T.; investigation, C.T., Z.A. and E.A.B.; resources, C.T., Z.A. and E.A.B.; data curation, C.T.; writing—original draft preparation, C.T.; writing— review and editing, C.T. and Z.A.; visualization, C.T. and Z.A.; supervision and project administration, C.T. All authors have read and agreed to the published version of the manuscript.

**Funding:** Our thanks to Elfi Kraka and Marek Freindorf of Texas Christian University for supplying the LMODEA software. Thanks also to the Body foundation which made possible the acquisition of software and computational resources used in the project. E.A.B. is particularly grateful to BAPKO of Marmara University providing computational resources through Grant No. FEN-A-071015-0477.

**Institutional Review Board Statement:** Not applicable. **Informed Consent Statement:** Not applicable.

**Data Availability Statement:** Not applicable.

**Conflicts of Interest:** The authors declare no conflict of interest.

**Sample Availability:** Samples of the compounds Not applicable; no chemical material is used in this research.
