Why the conductance is independent on the length of nanowire?

[hol28]

Hi everyone:
I calculated the conductance of Li-wires with different lengths and found that the values of conductance are almost the same. But as I know, the electrical conductivity is a material property and indepedent on the length and cross section of the material. However, the conductance, which equals conductivity*(cross section)/length, should be inversely proportional to the length. Could someone tell me why my calculated conductance is independent on the length?
Thanks very much! 

[zh]

The conductance in your calculation takes into account only the ballistic conduction.  What you expect is true for the  resistance of the Ohmic contact.

[hol28]

Thanks!

The conductance in your calculation takes into account only the ballistic conduction.  What you expect is true for the  resistance of the Ohmic contact.