Vaporization heat of niobium pentafluoride

Literary data on vapor composition above niobium pentafluoride are analyzed and incorrectness of the value of vaporization heat of NbF5 monomeric molecules, given in the Glushko reference book, is shown. Heat capacities of NbF5 gas for monomeric, two-dimensional, three-dimensional and four-dimensional NbF5 molecules are estimated and the vaporization heats of monomeric and polymeric forms at the melting temperature (in kJ/mol): 79.3(5.0)-NbF5, 71.0(6.7)-(NbF5)2, 53.9(4.6)-(NbF5)3, 44.5(6.7)-(NbF5)4, are calculated