[CPMD-list] how to do constraint optimization?

[Salomon Billeter]

Dear Lan-Feng,

which optimizer and which version of CPMD do you use? Depending on the
version of code and the type of optimizer, you could have hit a bug in the
constraints code (which was fixed once) which caused the optimization not
to converge.
Also, playing around with the PENALTY parameters could help. For geometry
optimization (except with RFO), CPMD does not calculate Lagrange
multipliers to satisfy the constraints but rather harmonically penalizes
the deviation from the target value.
Could you please send the input?

Best regards,
Salomon