\\ Species Tag:        &   29002 & Name:&  HCO+           
\\ Version:            &       4 & & Formyl cation / 
\\ Date:       &  Mar. 2007      & & Oxomethylium,
\\ Contributor:&  B. J. Drouin   & & X $^1 \Sigma ^+$ 
\\             &                 & & $nu_2$=0,1,2,$nu_1$=1,$nu_3$=1
\\ Lines Listed:       &     373 & Q(300.0)=&      145.9867 
\\ Freq. (GHz) $<$     &    3561 & Q(225.0)=&      106.5592 
\\ Max. J:             &      40 & Q(150.0)=&       70.4887
\\ LOGSTR0=            &   -10.0 & Q(75.00)=&       35.3833
\\ LOGSTR1=            &    -8.0 & Q(37.50)=&       17.8601
\\ Isotope Corr.:      &     0.  & Q(18.75)=&        9.1023 
\\ Egy. (cm$^{-1}$) $>$&     0.0 & Q(9.375)=&        4.7298
\\ $\mu_a$ = & 3.888             & A=& 
\\ $\mu_b$ = &                   & B=& 44594.4
\\ $\mu_c$ = &                   & C=& 
\headend 
 
The observed microwave lines are from R. C. Woods, T. A. Dixon, R. J.
Saykally, and P. G. Szanto, 1975, Phys. Rev. Lett. {\bf 35}, 1269; K.
V. L. N. Sastry, E. Herbst, and F. C. De Lucia, 1981, J. Chem. Phys.
{\bf 75}, 4169; and F. C. van den Heuvel and A. Dymanus, 1982, Chem.
Phys. Lett. {\bf 92}, 21, G. A. Blake, K. B. Laughlin, R. C. Cohen, K.
L. Busarow and R. J. Saykally, 1987, Astrophys. J. {\bf 316}, L45; E.
Hirota and Y. Endo, 1988, J. Mol. Spectrosc. {\bf 127}, 527, and V. Lattanzi, A. Walters, B. J. Drouin and J. C. Pearson, 2007, Astrophys. J. {\bf 662} 771-778, 2007.  The
observed infrared transitions were taken from P. B. Davies and W. J.
Rothwell, 1984, J. Chem. Phys. {\bf 81}, 5239; K. Kawaguchi, C. Yamada,
S. Saito and E. Hirota, 1985, J. Chem. Phys. {\bf 82}, 1750; P. B.
Davies, P. A. Hamilton and W. J. Rothwell, 1984, J. Chem. Phys. {\bf
81}, 1598; S. C. Foster, A. R. W. McKeller and T. J. Sears, 1984, J.
Chem. Phys. {\bf 81}, 578; C. S. Gudeman, M. H. Begemann, J. Pfaff and
R. J. Saykally, 1983, Phys. Rev. Lett. {\bf 50}, 727; T. Amano, 1983,
J. Chem. Phys. {\bf 79}, 3595; D.-J. Liu, S.-T. Lee and T. Oka, 1988,
J. Mol. Spectrosc. {\bf 128}, 236.

The vibrational state are as follows: v=0 is the ground, v=1 is $nu_2$=1
(bend), v=2 is $nu_2$=2 l=0 (bend), v=3 is $nu_3$=1 (C-O stretch), and
v=4 is $nu_1$=1 (C-H stretch). Only l=0 components for the $nu_2$=2
state have been reported.  These were fit to an effective Hamiltonian
as in E. Hirota and Y. Endo.

The dipole moment was estimated theoretically by Yamaguchi {\it et al.} 1994, J. Chem. Phys. {\bf 101}, 8945-8954
 and was assumed for all the states.