Dear all.
I have three regions:
region 1 nonrigid
region 2 nonrigid
region 3 rigid
The atoms in regions 1 and 2 can move in any direction but those in region 3 are fixed. When I do charge equilibration, the charges are fixed in region 3 but also in region 2. Is there any way to tell GULP to equilibrate charges also in region 2?
Thank you,
Roman
The manual says that charges are calculated only for atoms in region 1. Perhaps this is for Julian - implement a command qregion N that enforces calculation of charges in region N (besides N=1)?
Dear Roman,
The reason for the fixing of the charges is that in the original 2 region scenario where region 2 is representing the bulk below a surface then the charges have to be fixed at the bulk values. However, when the region option was generalised to more than 2 regions the charge fixing didn’t keep up. I’ll add an option, as suggested, to allow the user to control the fixing or varying of charges for different regions.
Regards,
Julian
Many thanks Julian. This would be immensely helpful.
Just a quick update - I’ve now added this feature to version 6.4 ready for release later this year.