THEORETICAL-STUDY OF HYDRAZOIC ACID AND METHYL AZIDE

State-of-the-art ab initio computations have been performed on the ground state of HN3 and CH3N3. The methods employed include Roothaan-Hartree-Fock molecular orbitals, single- and double-excitation configuration interaction, as well as modified-coupled-pair-functional approximations. The basis sets chosen for this study are the highly efficient atomic natural orbitals. The variational energies obtained are lower than previous studies and the dipole moments agree with experiment. The agreement between computed and observed nuclear quadrupole coupling constants is satisfactory, especially for N-alpha. It is suggested that improved agreement for the other N atoms requires vibrational averaging and possibly the use of the finite-field method.