Charge transfer upon interaction

Hi,

I’ve created two atoms with opposite charges so that they attract each other and once they attract and touch each other I want the charge to disappear. I’ve tried to obtain this using fix qeq and it’s variants but as soon as this fix is used atoms tend to change their initial charge even before they meet! Can you suggest something for my requirement?

Thanks

boddapar

In all variable charge methods charge is considered to be conserved, meaning you cannot create or destroy charges. You can not use fix qeq to do what you want. You will have to set charges to zero manually (set command).

Ray Shan

Hi,

I've created two atoms with opposite charges so that they attract each other
and once they attract and touch each other I want the charge to disappear.
I've tried to obtain this using fix qeq and it's variants but as soon as
this fix is used atoms tend to change their initial charge even before they
meet! Can you suggest something for my requirement?

if you want this kind of behavior you will have to program your own
fix or a custom pair style.
please note that suddenly turning off charges for a close contact will
result in a *massive* discontinuity for energy and forces and thus
either has to be performed gradually, or there has to be some
compensating force (e.g. through creating a bond).

is this some kind of published force field or implemented elsewhere?

axel.