# [CP2K-user] [CP2K:15488] Re: convergence problem

alberto santonocito albesan... at gmail.com
Tue Jun 1 12:44:20 UTC 2021

```Thanks!

Il giorno lun 31 mag 2021 alle ore 08:55 ma... at gmail.com <
ma455... at gmail.com> ha scritto:

> Hi,
>
> I think 1E-06 for "MAX_DR MAX_FORCE   RMS_DR    RMS_FORCE are too tight".
> 1/3 of the default value of cp2k should be tight enough.
>
> Regards,
> Hongyang
> 在2021年5月31日星期一 UTC+10 上午7:09:07<alberto> 写道：
>
>> Dear cp2k users,
>> I am doing the geometry optimization of a configuration (supercell
>> containing 4 molecules of Fe(CO)5 with symmetry C2/c and Z=4) but the
>> energy is locked on a value and is not decreasing.
>> How can I solve this problem?
>> Should I use a higher CUTOFF value?
>>
>>
>> *******************************************************************************
>>  ***                 BRENT   - NUMBER OF ENERGY EVALUATIONS :       1
>>     ***
>>
>>  *******************************************************************************
>>
>>  --------  Informations at step =   186 ------------
>>   Optimization Method        =                   SD
>>   Total Energy               =      -927.5280017548
>>   Real energy change         =         0.0000000000
>>   Decrease in energy         =                   NO
>>   Used time                  =             2410.831
>>
>>   Convergence check :
>>   Max. step size             =         0.0000000000
>>   Conv. limit for step size  =         0.0000010000
>>   Convergence in step size   =                  YES
>>   RMS step size              =         0.0000000000
>>   Conv. limit for RMS step   =         0.0000010000
>>   Convergence in RMS step    =                  YES
>>   Conv. limit for gradients  =         0.0000010000
>>   Conv. for gradients        =                   NO
>>   Conv. limit for RMS grad.  =         0.0000010000
>>   Conv. for gradients        =                   NO
>>  ---------------------------------------------------
>> I attach the input
>> Thanks
>>
>> --
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