[CP2K-user] [CP2K:15777] Re: The target temperature cannot be maintained during AIMD simulation process
Lucas Lodeiro
eluni... at gmail.com
Fri Jul 23 23:14:26 UTC 2021
I forgot to mention, when all commented things work well, if you want to
thermalize the system after running a production dynamics, it is advisable
to run the thermalization in two steps instead of just one run. I use a two
step procedure, running first a thermalization with a short TIMECON (50 or
100 fs) and REGION MASSIVE, to have a strong coupling and fast temperature
stabilization, then restart using a higher TIMECON (200 fs or what you want
for production) and REGION GLOBAL, restarting the thermostat between step 1
and 2. With this procedure usually you obtain a better thermalization in a
short number of steps.
Regards
El vie, 23 jul 2021 a las 14:12, Lucas Lodeiro (<eluni... at gmail.com>)
escribió:
> Hello Tingting Zhu,
>
> As far as I know, to correct your errors in EOM, you have to reduce the
> time step to 0.5 fs when hydrogen atoms are present and high temperature
> (fast dynamics) is applied. Also you have a poor performance in the SCF
> cycle. The most important is your convergence criterion, defined by
> EPS_SCF. with your current value 1.0E-5 you are having error on the energy
> in the order of E-3 E-4, which is very high. REDUCING EPS_SCF and
> EPS_DEFAULT probably solve in part these problem. I usually use a relation
> (EPS_SCF)^2=EPS_DEFAULT.
> Also, your CUTOFF is so low. You have to compute a convergence study
> first, to have good SCF results first, and then run the MD. At the forum,
> some people says a good guess for cutoff is REL_CUTOFF *
> HIGHER_GAUSSIAN_COEFFICIENT, in your case Mg has a hard PP, where the
> tighter gaussian has a coefficient of 30.65, then with a REL_CUTOFF=40 you
> need a CUTOFF=1200 or higher.
>
> Regards - Lucas Lodeiro
>
> El vie, 23 jul 2021 a las 8:01, 'Tingting Zhu' via cp2k (<
> cp... at googlegroups.com>) escribió:
>
>>
>> Dear Marcella Iannuzzi
>>
>> Ok, thank you! I will learn CP2K as your suggestion.
>>
>> However, for the problem you pointed "the integral error of the equation
>> of motion is large", I still don't know how to solve it? According to my
>> current understanding, may I increase the value of EPS_SCF, CUTOFF,
>> REL_CUTOFF, and decrease the value of TIMESTEP. Do you think it is
>> appropriate?
>> For example, ( EPS_DEFAULT 1E-12, EPS_SCF=1.0E*10^6, CUTOFF=350,
>> REL_CUTOFF=60, TIMESTEP=0.5)
>>
>> Sincerely
>> Tingting Zhu
>>
>>
>>
>>
>>
>>
>>
>>
>> 在2021年7月23日星期五 UTC+8 下午4:18:42<Marcella Iannuzzi> 写道：
>>
>>> Dear Tingting Zhu
>>>
>>> I quickly checked your energy file and indeed you have a serious drift
>>> in the total energy,
>>> which indicates that the integration of the equations of motion has a
>>> large error.
>>> If you do not have experience with ab initio MD, I suggest that you
>>> learn that first from reference literature.
>>> The parameters are adjusted until converged results are obtained and
>>> known properties are reproduced.
>>>
>>> Regards
>>> Marcella
>>>
>>>
>>> On Friday, July 23, 2021 at 9:30:06 AM UTC+2 fe... at qq.com wrote:
>>>
>>>> Dear Marcella Iannuzzi
>>>> Since I am a beginner, although I have read a lot of documents about
>>>> CP2K, I still lack experience in setting some parameters. In the input
>>>> file, could you give me some suggestions about the settings of CUTOFF, SCF,
>>>> EPS_SCF? There are 366 atoms in my system, containing Mg, Al, O, and H.
>>>> In addition, the input file, out file and corresponding trajectory file
>>>> that I calculated before are put in the compressed package below.
>>>>
>>>> The CP2K version I use is 7.1
>>>>
>>>> Thank you very much!
>>>>
>>>>
>>>>
>>>>
>>>> 在2021年7月23日星期五 UTC+8 下午2:49:54<Marcella Iannuzzi> 写道：
>>>>
>>>>> Dear Tingting Zhu
>>>>>
>>>>> One possible explanation is that the error in the forces and in the
>>>>> integration of the equations of motion is too big.
>>>>> Some parameters in the input would indicate that, as too large
>>>>> TIMESTEP and EPS_SCF and too low CUTOFF.
>>>>> This could be verified from the conservation of the total energy.
>>>>> Without more information it is difficult to guess.
>>>>>
>>>>> Regards
>>>>> Marcella
>>>>>
>>>>> On Friday, July 23, 2021 at 8:34:17 AM UTC+2 fe... at qq.com wrote:
>>>>>
>>>>>> Dear all,
>>>>>>
>>>>>> I am new to cp2k, I want to use CP2K's kinetics module to simulate
>>>>>> the adsorption of water on the surface of MgAl2O4 (111) at 973K. However,
>>>>>> with the increase of simulation time, the temperature keeps increasing, and
>>>>>> there is no trend to stablize at the target temperature. My input file is
>>>>>> as follows:
>>>>>>
>>>>>> I also tried to modify the TIMECON parameter to 200fs or 400fs, but
>>>>>> this problem always exists. Any idea whats going wrong here?
>>>>>>
>>>>>> I need your help, Please do correct me if any information provided
>>>>>> seems wrong
>>>>>>
>>>>>>
>>>>>> [image: 200-400 fs.png]
>>>>>> [image: 200 fs.png]
>>>>>>
>>>>>>
>>>>>> &GLOBAL
>>>>>> PROJECT MgAl2O4-14W-MD
>>>>>> PRINT_LEVEL LOW
>>>>>> RUN_TYPE MD
>>>>>> &END GLOBAL
>>>>>>
>>>>>> &FORCE_EVAL
>>>>>> METHOD Quickstep
>>>>>> &SUBSYS
>>>>>> &CELL
>>>>>> A 17.33280000 0.00000000 0.00000000
>>>>>> B 0.00000000 20.01420000 0.00000000
>>>>>> C 0.00000000 0.00000000 28.56250000
>>>>>> PERIODIC XYZ #Direction of applied PBC (geometry aspect)
>>>>>> &END CELL
>>>>>> &COORD
>>>>>> Al 0.0000000000 3.3357667100 1.6309187500
>>>>>> <(630)%20918-7500>
>>>>>> Al 2.8888577800 <(888)%20857-7800> 8.3393167100
>>>>>> <(339)%20316-7100> 1.6309187500 <(630)%20918-7500>
>>>>>> Al 5.7775422200 3.3357667100 1.6309187500
>>>>>> <(630)%20918-7500>
>>>>>> Al 8.6664000000 8.3393167100 <(339)%20316-7100>
>>>>>> 1.6309187500 <(630)%20918-7500>
>>>>>> Al 11.5552577800 3.3357667100 1.6309187500
>>>>>> <(630)%20918-7500>
>>>>>> ............
>>>>>> &END COORD
>>>>>> # &VELOCITY #You can set initial atomic velocities in this section
>>>>>> # &END VELOCITY
>>>>>> &KIND Al
>>>>>> ELEMENT Al
>>>>>> BASIS_SET DZVP-MOLOPT-SR-GTH
>>>>>> POTENTIAL GTH-PBE
>>>>>> &END KIND
>>>>>> &KIND Mg
>>>>>> ELEMENT Mg
>>>>>> BASIS_SET DZVP-MOLOPT-SR-GTH
>>>>>> POTENTIAL GTH-PBE
>>>>>> &END KIND
>>>>>> &KIND O
>>>>>> ELEMENT O
>>>>>> BASIS_SET DZVP-MOLOPT-SR-GTH
>>>>>> POTENTIAL GTH-PBE
>>>>>> &END KIND
>>>>>> &KIND H
>>>>>> ELEMENT H
>>>>>> BASIS_SET DZVP-MOLOPT-SR-GTH
>>>>>> POTENTIAL GTH-PBE
>>>>>> &END KIND
>>>>>> &END SUBSYS
>>>>>>
>>>>>> &DFT
>>>>>> BASIS_SET_FILE_NAME /home/room/data/cp2k-7.1.0/data/BASIS_MOLOPT
>>>>>> POTENTIAL_FILE_NAME /home/room/data/cp2k-7.1.0/data/POTENTIAL
>>>>>> # WFN_RESTART_FILE_NAME MgAl2O4-14W-MD-RESTART.wfn
>>>>>> CHARGE 0 #Net charge
>>>>>> MULTIPLICITY 1 #Spin multiplicity
>>>>>> &QS
>>>>>> EPS_DEFAULT 1E-10 #This is default. Set all EPS_xxx to values
>>>>>> such that the energy will be correct up to this value
>>>>>> EXTRAPOLATION ASPC #Extrapolation for wavefunction during e.g.
>>>>>> MD. ASPC is default, PS also be used
>>>>>> EXTRAPOLATION_ORDER 3 #Order for PS or ASPC extrapolation. 3 is
>>>>>> default
>>>>>> &END QS
>>>>>> &POISSON
>>>>>> PERIODIC XYZ #Direction(s) of PBC for calculating electrostatics
>>>>>> PSOLVER PERIODIC #The way to solve Poisson equation
>>>>>> &END POISSON
>>>>>> &XC
>>>>>> &XC_FUNCTIONAL PBE
>>>>>> &END XC_FUNCTIONAL
>>>>>> &VDW_POTENTIAL
>>>>>> POTENTIAL_TYPE PAIR_POTENTIAL
>>>>>> &PAIR_POTENTIAL
>>>>>> PARAMETER_FILE_NAME dftd3.dat
>>>>>> TYPE DFTD3
>>>>>> REFERENCE_FUNCTIONAL PBE
>>>>>> &END PAIR_POTENTIAL
>>>>>> &END VDW_POTENTIAL
>>>>>> &END XC
>>>>>> &MGRID
>>>>>> CUTOFF 300
>>>>>> REL_CUTOFF 40
>>>>>> &END MGRID
>>>>>> &SCF
>>>>>> MAX_SCF 500 #Maximum number of steps of inner SCF
>>>>>> EPS_SCF 1.0E-05 #Convergence threshold of density matrix of
>>>>>> inner SCF
>>>>>> # SCF_GUESS RESTART #Use wavefunction from WFN_RESTART_FILE_NAME
>>>>>> file as initial guess
>>>>>> &OT
>>>>>> PRECONDITIONER FULL_KINETIC #FULL_SINGLE_INVERSE is also
>>>>>> worth to try. FULL_ALL is better but quite expensive for large system
>>>>>> MINIMIZER DIIS #CG is worth to consider in difficult cases
>>>>>> LINESEARCH 2PNT #1D line search algorithm for CG. 2PNT is
>>>>>> default, 3PNT is better but more costly. GOLD is best but very expensive
>>>>>> &END OT
>>>>>> &OUTER_SCF
>>>>>> MAX_SCF 500 #Maximum number of steps of outer SCF
>>>>>> EPS_SCF 1.0E-05 #Convergence threshold of outer SCF
>>>>>> &END OUTER_SCF
>>>>>> &PRINT
>>>>>> &RESTART #Use "&RESTART OFF" can prevent generating wfn file
>>>>>> BACKUP_COPIES 0 #Maximum number of backup copies of wfn file
>>>>>> &END RESTART
>>>>>> &END PRINT
>>>>>> &END SCF
>>>>>> &END DFT
>>>>>> &END FORCE_EVAL
>>>>>>
>>>>>> &MOTION
>>>>>> &MD
>>>>>> ENSEMBLE NVT
>>>>>> STEPS 5000
>>>>>> TIMESTEP 1.0 #fs. Decrease it properly for high temperature
>>>>>> simulation
>>>>>> TEMPERATURE 973 #Initial and maintained temperature (K)
>>>>>> &THERMOSTAT
>>>>>> TYPE CSVR
>>>>>> &CSVR
>>>>>> TIMECON 200 #Time constant in fs. Smaller/larger results in
>>>>>> stronger/weaker temperature coupling
>>>>>> &END CSVR
>>>>>> &DEFINE_REGION
>>>>>> LIST 193..366
>>>>>> &END DEFINE_REGION
>>>>>> &END THERMOSTAT
>>>>>> &END MD
>>>>>> &CONSTRAINT
>>>>>> &FIXED_ATOMS #Set atoms to be fixed
>>>>>> COMPONENTS_TO_FIX XYZ #May also be e.g. Z, XY ...
>>>>>> LIST 1..192
>>>>>>
>>>>>> &END FIXED_ATOMS
>>>>>> &END CONSTRAINT
>>>>>> &PRINT
>>>>>> &TRAJECTORY
>>>>>> &EACH
>>>>>> MD 1 #Output frequency of geometry
>>>>>> &END EACH
>>>>>> FORMAT xyz
>>>>>> &END TRAJECTORY
>>>>>> &VELOCITIES
>>>>>> &EACH
>>>>>> MD 1 #Output frequency of velocity
>>>>>> &END EACH
>>>>>> &END VELOCITIES
>>>>>> &RESTART
>>>>>> BACKUP_COPIES 0 #Maximum number of backing up restart file
>>>>>> &EACH
>>>>>> MD 10 #Frequency of updating last restart file
>>>>>> &END EACH
>>>>>> &END RESTART
>>>>>> &END PRINT
>>>>>> &END MOTION
>>>>>>
>>>>>> Thanks in advance!
>>>>>>
>>>>>> Sincerely
>>>>>> Tingting Zhu
>>>>>>
>>>>>>
>>>>>> --
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