[Ciara]

What are the potential sources of residual (or zero-point) entropy at 0K? All the diatomics, HX, where X is H or a halogen, have a significant residual entropy. What would you expect to be the major contribution in the cases of
1) H2 (S=6.4JK-1mol-1 at 0K)
2) HF (S=5.9JK-1mol-1 at 0K)
3) HCl (S=4.3JK-1Mol-1 at 0K)

please help 

[cpncoop]

brownian motion?