Reference Label	Details
Ruscic G3B3	G3B3LYP calculation; B3LYP/6-31G(d) frequencies are scaled by 0.9614 (see Scott 1996)
est unc	estimated uncertainty
Grunenberg 2003	J. Grunenberg, R. Streubel, G. von Frantzius, and W. Marten, J. Chem. Phys. 119, 165-169 (2003) The Strongest Bond in the Universe? Accurate Calculation of Compliance Matrices for the ions N2H+, HCO+, and HOC+