[gmx-users] vanadium non-bonded parameters

[Gonçalo C. Justino]

Dear gmx'ers,

Does anyone know of any (published or not) non-bonded parameters for
vanadium species for any of the forcefields implemented in GROMACS ?

If not, my question is: what is the meaning of the null values for
sigma and epsilon in, e.g., amber03, for Fe:

FE          26      55.00    0.0000  A   0.00000e+00  0.00000e+00
[from the ffnonbonded.itp file]

Thks for any help,
Gonçalo