${session.getAttribute("locale")} 5 Ab initio rovibrational spectrum of the NaH₂⁺ ion-quadrupole complex and angle <θ> were 2.4995 Å and 17.1°, respectively. The ab initio (¹A₁) NaH₂⁺ PES yielded a dissociation energy (D₀) value of 10.3 kJ mol⁻¹, which is in excellent agreement with the experimental value of 10.3 ± 0.8 kJ mol⁻¹ (Bushnell et al. in J Phys Chem 98:2044, 1994). An analytical dipole moment surface was constructed using 90 CCSD(T) points. Rovibrational spectra of (¹A₁) NaH₂⁺, (¹A') NaHD⁺ and (¹A₁) NaD₂⁺ for v ≤ 10, J ≤ 5 were constructed using rovibrational transition moment matrix elements calculated in a novel manner that employs the analytical dipole moment surface (DMS). The rovibrational structure of the Na⁺-H₂ vHH = 1 ← vHH = 0 band was calculated and compared to that of Li⁺-H₂.]]> Wed 24 Jul 2013 22:44:49 EST ]]>