[CP2K-user] [CP2K:15777] Re: The target temperature cannot be maintained during AIMD simulation process
Lucas Lodeiro
eluni... at gmail.com
Fri Jul 23 17:12:34 UTC 2021
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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