[CP2K:3117] Metadynamics Bug report in colvar: DISTANCE

[Bernd Ensing]

Dear people,

I would like to perform a constrained geometry optimazation with
Quickstep. I have defined a torsion collective variable in the &SUBSYS
part of the input:
===================================================================
    &COLVAR
      &TORSION
        ATOMS 1 2 3 4
      &END
    &END
===================================================================

and a constraint definition in the &MOTION section:

===================================================================
  &CONSTRAINT
    &COLLECTIVE
      TARGET -1.3788
      MOLECULE 1
      COLVAR 1
    &END COLLECTIVE
  &END CONSTRAINT
===================================================================

but for some reason I get the following error at the end of the output:

===================================================================
         ----------------------------------------------------------------------
 COLVARS| COLVAR INPUT INDEX:        1
 COLVARS| TORSION       >>> ATOMS:                     1       2       3       4
          ----------------------------------------------------------------------

 CELL_TOP| Volume [angstrom^3]:                                         8000.000
 CELL_TOP| Vector a [angstrom    20.000     0.000     0.000    |a| =      20.000
 CELL_TOP| Vector b [angstrom     0.000    20.000     0.000    |b| =      20.000
 CELL_TOP| Vector c [angstrom     0.000     0.000    20.000    |c| =      20.000
 CELL_TOP| Angle (b,c), alpha [degree]:                                   90.000
 CELL_TOP| Angle (a,c), beta  [degree]:                                   90.000
 CELL_TOP| Angle (a,b), gamma [degree]:                                   90.000
    |  Error in constraints setup!
    |  A constraint has been defined for a molecule type
    |   but the atoms specified in the constraint and the atoms defined for
    |   the molecule DO NOT match!
    |  This could be very probable due to a wrong connectivity, or an error
    |   in the constraint specification in the input file.
    |   Please check it carefully!
    |  Error in constraints setup!
GENERATE|  Preliminary Number of Bonds generated:                             0
 GENERATE|  Achieved consistency in connectivity generation.
 GENERATE|  Number of Bonds generated:                                         0
 GENERATE|  Preliminary Number of Bends generated:                             0
 GENERATE|  Number of Bends generated:                                         0
 GENERATE|  Number of UB generated:                                            0
 GENERATE|  Preliminary Number of Torsions generated:                          0
 GENERATE|  Number of Torsions generated:                                      0
 GENERATE|  Number of Impropers generated:                                     0
 GENERATE|  Number of 1-4 interactions generated:                              0
    |  Error in constraints setup!
    |  A constraint has been defined for a molecule type
    |   but the atoms specified in the constraint and the atoms defined for
    |   the molecule DO NOT match!
    |  This could be very probable due to a wrong connectivity, or an error
    |   in the constraint specification in the input file.
    |   Please check it carefully!
 *
 *** 15:06:36 ERRORL2 in topology_constraint_util:setup_lcolv processor     ***
 ***   0  err=-300  condition FAILED at line 1201                           ***
 *

 ===== Routine Calling Stack =====

            4 topology_constraint_pack
            3 topology_control
            2 quickstep_create_force_env
            1 CP2K
 CP2K| condition FAILED at line 1201
 CP2K| Abnormal program termination, stopped by process number 0
===================================================================


What I understand from this error message is that it compares the
atoms in the torsion collective variable with the atoms in the
topology, which then don't seem to match. Mind you that this is not a
classical forcefield run, so I don't quite understand what is meant
with a topology.
In any case, there are more than 4 atoms in the system, so specifying
atoms 1, 2, 3, 4 in the collective variable should be fine, I thought.
Does anybody understand this error and knows how to fix it?

many thanks in advance,

Bernd Ensing