Vibrational fundamentals of ketene, H2CCO,
and vibrational correction factors to the partition function (at the bottom) 
calculated in the harmonic approximation.
The data may be used for isotopologs 
with 13C or 18O substition with small errors; 
for isotopologs with D at least modest errors occur.

The fundamentals were taken from

1) L. Nemes, D. Luckhaus, M. Quack, J. W. C. Johns, 
2000, J. Mol. Struct., 517-518, 217-236;
https://ui.adsabs.harvard.edu/abs/2000JMoSt.517..217N/abstract
https://doi.org/10.1016/S0022-2860(99)00253-7
for modes 9, 6, 5, and 8.

2) J. L. Duncan, A. M. Ferguson, J. Harper, K. H. Tonge, and F. Hegelund,
1987, J. Mol. Spectrosc., 122, 72-93;
https://ui.adsabs.harvard.edu/abs/1987JMoSp.122...72D/abstract
https://doi.org/10.1016/0022-2852(87)90219-0
for modes 4, 3, 2, and 1.

3)  J. W. C. Johns, J. M. R. Stone, and G. Winnewisser, 
1972, J. Mol. Spectrosc., 42, 523-535;
https://ui.adsabs.harvard.edu/abs/1972JMoSp..42..523J/abstract
https://doi.org/10.1016/0022-2852(72)90227-5
for mode 7.

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mode / E(cm-1)
 9 /  439.374
 6 /  526.074
 5 /  587.433
 8 /  977.682
 4 / 1116.0
 3 / 1387.5
 2 / 2152.6
 1 / 3070.4
 7 / 3165.30

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T (K)     F(vib)
300.0    1.3406
225.0    1.1326
200.0    1.0861
180.0    1.0568
160.0    1.0342
150.0    1.0254
140.0    1.0181
120.0    1.0079
100.0    1.0025
 75.0    1.0003
 37.5    1.0000
 18.75   1.0000
  9.375  1.0000

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