<div dir="ltr"><div>Dear all,</div><div><br></div><div>I'm performing a constrained MD simulation where I have constrained 10 distances. The simulation is long so I have broken the simulation in parts of 100000 steps each, each time using the previous *-1.restart file as a starting point. <br></div><div><br></div><div>The problem is that every time I restart the simulation I see an obvious discontinuity in the *-1.LagrangeMultLog file. This discontinuity is observed every 600000 lines in the  *-1.LagrangeMultLog file as shown by the red arrow in the three examples pictures attached corresponding to lines 600000, 1200000 and 1800000. This discontinuity is not observed in the trajectory file or any other file. <br></div><div><br></div><div>Moreover, ignoring the fact that I could have some problem in how I restart the simulation, you can see an obvious trend for the lagrange multipliers to increase within each restart calculation. This increase is also not justified by any other file outputted by cp2k.</div><div><br></div><div> It appears to me some kind of cumulative error within the calculation of the lagrange multipliers. Any ideas of why could this be, or how to solve it?</div><div><br></div><div>Best regards,</div><div><br></div><div>Alejandro.</div><div><br></div><div><br></div><div>PD: My input file looks like this:</div><div><br></div><div><br></div>                                           <br><br>@SET basis TZV2P-GTH<br>@SET aux_basis cFIT3<br><br> <br>@SET n_steps 100000<br>@SET ABC 20<br>@SET project_name 30_r20_ts_p_80_rep_equi_5_atm_cons_pmf<br>@SET rest_file 30_r20_ts_p_80_rep_equi_5_atm_cons_pmf-1.restart<br>@SET LIBPATH /cluster/physics/CP2K/6.0/data<br>@SET sys 30_r20_ts_p_80_rep<br>@SET natm 33<br>@SET job md<br>@SET i 5<br><br>  &GLOBAL<br>        PRINT_LEVEL  LOW<br>        PROJECT_NAME $project_name<br>        RUN_TYPE  $job<br>  &END GLOBAL<br><br>  @IF ($i /= 1)<br>     &EXT_RESTART<br>           RESTART_FILE_NAME $rest_file<br>     &END EXT_RESTART<br>  @ENDIF <br>                                                              <br> <br>&MOTION<br>      &MD<br>         ENSEMBLE NVT<br>         STEPS $n_steps<br>         TIMESTEP 0.5<br>         TEMPERATURE 298<br><br>         ANGVEL_TOL 1<br>         ANGVEL_ZERO TRUE<br><br>@IF ($i == 1)<br>         STEP_START_VAL 0<br>         TIME_START_VAL 0<br>@ENDIF<br><br>         &THERMOSTAT<br>             TYPE NOSE<br>             REGION GLOBAL<br>             &NOSE<br>                 TIMECON 100<br>             &END NOSE<br>         &END THERMOSTAT<br>      &END MD<br><br>      &PRINT<br>           &TRAJECTORY<br>              &EACH<br>                   MD 10<br>              &END<br>           &END<br><br>           &RESTART                                    <br>                 &EACH    <br>                          MD $n_steps<br>                 &END<br>           &END<br>           &RESTART_HISTORY                            <br>              &EACH                  <br>                          MD $n_steps<br>              &END<br>          &END<br><br>&END<br>        <br><br>       &CONSTRAINT<br><br>                @INCLUDE collective.inp<br>                <br>                &LAGRANGE_MULTIPLIERS<br>                    COMMON_ITERATION_LEVELS 1<br>                &END LAGRANGE_MULTIPLIERS<br>       &END  CONSTRAINT<br>         <br>&END MOTION<br><br><br> &FORCE_EVAL<br>   METHOD  QS<br>    <br><br>   &DFT<br>      BASIS_SET_FILE_NAME  ${LIBPATH}/BASIS_MOLOPT<br>      POTENTIAL_FILE_NAME  ${LIBPATH}/GTH_POTENTIALS<br>      WFN_RESTART_FILE_NAME ${project_name}-RESTART.wfn<br>      <br>    &MGRID<br>      NGRIDS 5<br>      CUTOFF 400<br>      REL_CUTOFF 60<br>      COMMENSURATE<br>    &END MGRID<br>    <br>    &POISSON<br>            PERIODIC NONE<br>            POISSON_SOLVER WAVELET<br>    &END POISSON<br><br> &QS<br>      EPS_DEFAULT 1.0E-10<br>      EXTRAPOLATION ASPC<br>      EXTRAPOLATION_ORDER 3<br>      EPS_PGF_ORB 1.0E-12<br>      METHOD DFTB<br>            &DFTB<br>                   SELF_CONSISTENT    T<br>                   DISPERSION  T<br>                   DO_EWALD           F<br>                   HB_SR_GAMMA        T<br>                   &PARAMETER<br>                        PARAM_FILE_PATH  /users/ar612/data_base/dftb/3ob-3-1<br>                        PARAM_FILE_NAME  3ob-parameter<br>                        DISPERSION_TYPE D3<br>                        DISPERSION_PARAMETER_FILE dftd3.dat<br>                        D3_SCALING  1.0 1.5 1.5<br>                        HB_SR_PARAM       4.85<br>                  &END PARAMETER<br>           &END DFTB<br>    &END QS   <br>    <br>    <br>    <br>    &SCF<br>      MAX_SCF 100<br>      EPS_SCF 1.0E-5<br>      SCF_GUESS RESTART<br>      &OT<br>        PRECONDITIONER FULL_SINGLE_INVERSE<br>        MINIMIZER DIIS<br>      &END OT<br>      &OUTER_SCF<br>        MAX_SCF 20<br>        EPS_SCF 1.0E-5<br>      &END<br><br>    &END SCF<br><br>  &END DFT<br><br><br><br><br><br>   <br>   &SUBSYS<br>     &CELL<br>       A     ${ABC}   0   0    <br>       B     0    ${ABC}  0<br>       C     0    0   ${ABC}<br>       PERIODIC  NONE<br>     &END CELL<br><br>     @INCLUDE colvar.inp<br><br>     &TOPOLOGY<br>       COORD_FILE_NAME ${sys}.xyz<br>       COORD_FILE_FORMAT  XYZ<br>       NUMBER_OF_ATOMS  ${natm}<br>     &END TOPOLOGY<br>   &END SUBSYS<br> &END FORCE_EVAL<br><br></div>