The effect of substitution on the potential energy surfaces of RE 13 ≡AsR (E 13 = group 13 elements; R = F, OH, H, CH 3 , and SiH 3) is determined using density functional theory (M06-2X/Def2-TZVP,B3PW91/Def2-TZVP, and B3LYP/LANL2DZ+dp). The computational studies demonstrate that all triply bonded RE 13 ≡AsR species prefer to adopt a bent geometry that is consistent with the valence electron model. The theoretical studies also demonstrate that RE 13 ≡AsR molecules with smaller substituents are kinetically unstable, with respect to the intramolecular rearrangements. However, triply bonded R′E 13 ≡AsR′ species with bulkier substituents (R′ = SiMe(SitBu 3) 2 , SiiPrDis 2 , and NHC) are found to occupy the lowest minimum on the singlet potential energy surface, and they are both kinetically and thermodynamically stable. That is to say, the electronic and steric effects of bulky substituents play an important role in making molecules that feature an E 13 ≡As triple bond as viable synthetic target.