Figure 1 NICS(0) values of Cu3* at different levels of theory. Numbers | to 17 on the horizontal axis denote different basis sets which are employed for geometry optimization and computation of NICS values: (1) Aug-cc-pVDZ-PP, (2) Aug-cc-pVTZ-PP, (3) Lanl2DZ, (4) Lanl2TZ, (5) Lanl2TZ(f), (6) DZVP (DFT orbital), (7) cc-pWDZ-PP, (8) cc-pWTZ-PP, (9) Def2-TZVP, (10) Def2-TZVPP, (11) Def2-QZVP, (12) Def2-QZVPP, (13) 6-311G(d), (14) 6-311+G(d), (15) aug-cc-pVDZ, (16) aug-cc-pVTZ and (17) aug-cc-pVQZ. The absolute values of the isotropic NICS(0) are larger than those of the out-of-plane NICS; this shows that in contrast to the considered hydrocarbons, in-plane (ring) electronic current in Li;* is not the most effective electronic current in the cluster. It is worth mentioning that the situation is reversed in NICS(1); the absolute values of the out-of-plane NICS(1) are larger than those of the isotropic NICS. It is also suggested that the negative NICS in the centre of this cluster is somehow related to the presence of a non-nuclear attractor in the centre of this species.2!?* In order to estimate the influence of geometry variation, arising from the method/basis set dependence of geometry, on the magnitude of NICS in this cluster, NICS values at various levels of theory were computed at the geometry of Def2-QZVPP, the largest studied basis set, with three functionals. Tables S-13 and S-25+ show the differences between NICS values at the optimized geometries and those computed at the fixed geometries (ANICS values), and the variations in bond lengths due to the influence of various methods/basis sets (ABL). ABL just like ANICS is defined by comparing the bond length of the cluster Table S-2+ and Fig. 1 show that the type of employed basis set affects considerably the magnitude of NICS(0) values,