Elastic squared form factor and binding effect of carbon dioxide studied by the high resolution X-ray scattering

The elastic squared form factor of gaseous carbon dioxide was measured for the first time by high resolution X-ray scattering to separate the elastic and inelastic scattering. Bond lengths of rCO = 1.172 ± 0.008 Å and rOO = 2.344 ± 0.016 Å of CO2 were determined from the measured elastic squared form factors, which are in good agreement with the NIST benchmark data of rCO = 1.1621 Å and rOO = 2.3242 Å. Moreover, the obtained elastic squared form factor difference shows a clear binding effect in the region of small momentum transfers. The present work shows that high resolution X-ray scattering is a powerful tool to study the binding effect of molecules.