Isocyanide-nitrile rearrangement has long been a continuing and interesting topic. A series of nitriles isocyanides with the substituents R = -AlH2, -BeH, -BH2, -C≡CH, -CF3, -CH3, -Cl, -C≡N, -COOH, -F, -H, Li, -MgH, -Na, -NH2, -NO2, -OH, -PH2, -SH, -SiH3, -CH CH2 were investigated systematically based on full optimization at B3LYP-D3(BJ)/def2-QZVP level, isomerization energies from R–C≡N to:C N...