In simple molecules the bond moduli may be calculated from the frequencies of the vibrational modes using
where 
is the reduced mass and 
is the vibrational
frequency. The frequencies of the vibrational modes were calculated
for each molecular species using an ab initio technique described
in [39]. The results of these calculations are given in Table
.
| Molecule |  |  | (A.U.) |  |
 | 0.63 | 4204 | 0.50 | 521 |
| CO | 0.92 | 2172 | 6.86 | 1909 |
 | 0.93 | 722 | 16.03 | 492 |
 | 1.32 | 2200 | 7.00 | 1998 |
| SiO | 0.97 | 1209 | 10.18 | 878 |
 | 0.54 | 3807 | 1.00 | 855 |
 | 0.59 | 2617 | 1.00 | 404 |