Name
XYZ — Optimization to proceed in Cartesian space.
Description
This keyword requires that AMPAC runs the
geometry optimization in Cartesian coordinates rather than the default internal coordinate
system. If the geometry is provided to AMPAC in
Cartesian coordinates, a full 3N coordinate optimization is executed in Cartesian space. By default,
the geometry is reoriented to a z-matrix orientation but this can be avoided and the original Cartsian
framework maintained by using this the
ORIENT=ORIGINAL keyword. If the
geometry is provided to AMPAC in internal coordinates,
the keyword XYZ causes it to be converted to Cartesian coordinates, retaining the optimization
flags, except for the first six which are set to zero, leading to a 3N-6 Cartesian geometry
optimization. This allows an optimization to be run in a subset of the Cartesian coordinates.
