unrestricted singlet

[William]

Dear all,

I want to know if it is possible to calculate unrestricted singlet
state using cp2k.

I saw the O2 triplet input in QS test directory. The triplet case is
okay. But I tried an unrestricted singlet using the following
settings, it crashed.
==================================
    MULTIP 1
    ROKS
    &LOW_SPIN_ROKS
       ENERGY_SCALING 1.0 -1.0
       SPIN_CONFIGURATION 1 2
       SPIN_CONFIGURATION 1 2
    &END
==================================

Can anybody tell me if the setting is incorrect or due to other
reason?

Many thanks in advance!

Best,
William