Spectroscopicallly accurate calculated properties of H2

Diatomic hydrogen, H2, is the most abundant molecule in the universe and is therefore important in a variety of astrophysical studies. The possible cosmological time variation of physical constants, such as proton-electron mass ratio, is one example which can be probed with spectroscopic properties of H2, like the rovibrational binding energies. The Born-Oppenheimer approximation can be used in the calculation of the rovibrational binding energies, which are the solutions to the Schrdinger equation. However, to achieve the most accurate calculations, the approximation must be corrected for the effects that are not considered. With the corrections, the resulting calculations are close to the experimental results. The rovibrational energies and wave functions are used to calculate the probabilities of transitions between the rovibrational levels that are due to the quadrupole moment of H2. The transition probabilities and the energies are used to calculate the cooling function in the limit of large density.