- #1
aihaike
- 55
- 0
Dear all,
I'm trying to compute the dynamical matrix of a crystal with a pair potential.
One way would be to use the second derivatives of the potential, and an other is to compute it numerically.
Well, in both cases, I get troubles where atom i equal atom j.
Is there something I haven't get yet?
I go through each atoms (i=1,N) and for each pairs I go through each coordinates (x,y,z). But in the analytical expressions of the derevatives there is always 1/r which diverge when r=0.
Numerically I face to the same problem ...
Any advices?
Thanks in advance,
Eric.
I'm trying to compute the dynamical matrix of a crystal with a pair potential.
One way would be to use the second derivatives of the potential, and an other is to compute it numerically.
Well, in both cases, I get troubles where atom i equal atom j.
Is there something I haven't get yet?
I go through each atoms (i=1,N) and for each pairs I go through each coordinates (x,y,z). But in the analytical expressions of the derevatives there is always 1/r which diverge when r=0.
Numerically I face to the same problem ...
Any advices?
Thanks in advance,
Eric.