Hi all, I?m a bit confused about the various constraint types that one can apply during optimizations. I?m trying to perform a generalized stacking fault calculation wherein atoms in the top- and bottom-most layers will be fixed in the direction of the fault plane normal (in order to limit relaxation in this direction) and atoms in the top-half of the system will be constrained in the shifting direction (a <112> direction for an FCC lattice). You?ll note that these two sets intersect and have some atoms in common.
I?m trying to use the ?bennett_proj? type of constraint for this calculation, but it?s not clear to me whether atoms (a) are constrained to move ONLY along the vector direction specified, or (b) are constrained FROM moving along the vector direction specified. If (a), is there a way to restrict motion to a plane rather than a line? Is there a better way to do this calculation? Thank you, Jon Z. ---------------------------------- Jonathan A. Zimmerman Sandia National Laboratories E-mail: jzimmer at sandia.gov ------------------------------------------
