Constraint optimization
=======================

This input runs 4 calculations on the water molecule. In all 4 calculations
one OH bond length is constraint, the other one is optimized as well as the
bond angle. However the geometries are specified slightly differently:

h2o_c1:   The symmetry option is used to turn all symmetry off.
          The resulting calculation works as it should.

h2o_c2v:  The input geometry is symmetric but the constraint is asymmetric
          and autosym is not turned off.
          The code now correctly finds Cs symmetry and completes the
          optimization is performed correctly.

h2o_cs:   The input geometry is asymmetric otherwise everything is the same
          as with the h2o_c2v geometry.
          The resulting calculation correctly sees the two bondlengths as
          different and applies the constraints in the correct way.

h2o_cart: The input geometry is specified using Cartesian coordinates and
          the constraints are imposed using the geometry adjust; zcoord;
          mechanism.
          The code detects Cs symmetry correctly also in this case and
          completes the geometry optimization correctly.

If correct then all four calculations should arrive at the same answer,
following the same optimization path. Making the auto-symmetry code aware
of any constraints on the geometry fixed the optimization problems we had
before.