Question

Is there any chance that someone in here knows how to use the Albrecht Unsold approximation for dispersion force?

Answer 1

from wikipedia: The quantities and are the first ionization potentials of the atoms and is the intermolecular distance.

Note that this final London equation does not contain instantaneous dipoles

Answer 2

I have the R and IE values I was unsure about a couple things the alpha/susceptibility values and also whether the negative in the resulting is supposed to be there(or if maybe a value that I put in was really supposed to be negative)? I ended up with -5.87x10^-10 for fluorine and -8.28x10^-11 for bromine. If the -3/2 at the beginning of the approximation is simply derived from Hooke's law and indicative only of the direction of the force, then if I understand correctly that would mean bromine actually should have weaker intermolecular forces than fluorine does.

This of course would not be the case in the real world but I actually intended to calculate for what would happen in a hypothetical isolated system.

Answer 3

oh the values I used for the susceptibility values were from papers I found the one for fluorine was from http://pubs.acs.org/doi/abs/10.1021/j100475a015 the author was arguing that the 2nd order correlation correction of CHF polariziability of the F- ion should be much higher than previous calculated values.(the paper is old and therefore the values may be out of date.) The value I found for bromine was from http://watercluster.ucoz.ru/High_Temp_2011.pdf the article was more current but the fact that I am a first year student in physics atm quite probably means that these sources may not be appropriate. Any help that I could getting vetting my results would be great.

Answer 4

Seems to be quite advanced for a first year student. ! Which college?

Answer 5

It isn't work for a class it's just for fun. Im studying at UCCS though.