Repulsive term in Born-Mayer potentials

[sphericalCat]

Hi, folks,

Is the exponential (repulsive) term in Born-Mayer potentials supposed to be exp(-r) or exp(1/r)? - r is the interatomic distance; constants ignored

I've seen both versions pop up in what appear to be reputable sources. The second one seems to be more popular, but, to me at least, the first one seems to make more sense (goes to infinity at r=0).

Which one is the right one and why?

Thanks

 

[marlon]

Hi, folks,

Is the exponential (repulsive) term in Born-Mayer potentials supposed to be exp(-r) or exp(1/r)? - r is the interatomic distance; constants ignored

I've seen both versions pop up in what appear to be reputable sources. The second one seems to be more popular, but, to me at least, the first one seems to make more sense (goes to infinity at r=0).

Which one is the right one and why?

Thanks

Check out : Phys. Rev. 178, 76 (1969)

The exp(-r) describes the short term repulsive interaction. Aside the Coulombic part (1/r) there are socalled "dispersion interactions of the ions". These terms are always attractive and are present due to the effect of perturbations in an ion's electron distribution on a neighbouring ion's electron distribution. Check ou the third term in http://nickwilson.co.uk/research/ox.ac.uk/Part2/node4.html

I did not find the exp(r) part. Could you show me reference where this mentioned ?

marlon