[gmx-users] L-J question

[Anthony Cruz]

Hi users:
I have a little question. I found some L-J parameters for heme iron for the 
GROMOS87 FF and I want to use it in the GROMOS ff43a1 . The units as appear 
in the paper [biophys. J. 1995 (69) p810] A(kJ nm^ -12 mol ^-1) 4.30115e-5 
and B (kJ nm^ -6 mol ^ -1) 8.886909e-3.  I need to make any changes to the 
values there is any convertion factor??

Also I found other L-J parameters [J. Phys. Chem. B 2002 (106) p12031] the 
unit for this other are A[(kcal/mol)/A^12] 10389.5 and B[(kcal/mol)/A^6] 
288.3 also appear the fallowing equation Vnb(rij) =Aijrij^ -12 - Bijrij ^ -6 
with Aij(Bij) the geometric means of Ai and Aj(Bi and Bj).  How I can 
inplemet this values to use it in the GROMOS ff43a1????

Thank you for your help!

Best regards
Anthony