The molecular structure of niobium pentachloride by quantum chemical calculations and gas electron diffraction

Abstract The molecular structure of NbCl 5 was determined experimentally by gas electron diffraction and computationally by structure optimisation of D 3h models. The bond distances obtained by ab initio calculations with very large basis sets, relativistic effects included through the one-electron Douglas–Kroll method and all electrons correlated at the MP2 level and by gas electron diffraction are: (calc/exp) Nb–Cl ax =230.7/230.6(5) pm and Nb–Cl eq =227.0/227.5(4) pm.