[CP2K-user] EXTERNAL_PRESSURE and PRESSURE_TOLERANCE settings in cell optimisations for crystals
Huaiyang Sun
shyf... at gmail.com
Wed Nov 25 15:49:59 UTC 2020
Thank you, Matt. I've found a TZVP-MOLOPT-SR-GTH-q11basis set for Y in
BASIS_MOLOPT_UCL.
Sincerely,
Huaiyang Sun
On Wednesday, November 25, 2020 at 10:48:55 PM UTC+8 Matt W wrote:
> You can find some good quality basis sets in in BASIS_MOLOPT_UCL:
>
> https://github.com/cp2k/cp2k/blob/master/data/BASIS_MOLOPT_UCL
>
> there are also some alternative Lanthanide basis sets available in other
> files.
>
> Matt
>
> On Wednesday, November 25, 2020 at 2:44:47 PM UTC sh... at gmail.com wrote:
>
>> Dear Fabian,
>> Thanks for the explanation! I've noticed the CELL_REF and OT issues of
>> the input file. The CP2K output file also hints about the OT algorithm.
>> The reason I use DZV-GTH-PADE basis for Y is that I cannot find GTH-PBE
>> basis set for it in the cp2k/data directory. Maybe I should find the
>> corresponding basis set in somewhere else.
>> Anyway, thanks for your help and suggestions!
>>
>> Best regards.
>> Huaiyang Sun
>>
>> On Wednesday, November 25, 2020 at 3:26:58 PM UTC+8 fa... at gmail.com
>> wrote:
>>
>>> Dear Huaiyang Sun,
>>>
>>> Many solids have a bulk modulus in the range of 1 to 100 GPa. A material
>>> with a bulk modulus of 10 GPa changes its volume by 1% when subjected to a
>>> pressure of 1000 bar. In this case a PRESSURE_TOLERANCE of 100 bar is
>>> already accurate to within 0.1% of the volume.
>>>
>>> The input file has some issues:
>>> use CELL_REF for a cell optimization
>>> you cannot use OT together with k-points, use DIAGONALIZATION instead
>>> I would recomment to not mix different basis sets, especially not using
>>> PADE ones for PBE calculations
>>>
>>> Cheers,
>>> Fabian
>>> On Wednesday, 25 November 2020 at 04:09:02 UTC+1 sh... at gmail.com
>>> wrote:
>>>
>>>>
>>>> Deal all,
>>>>
>>>> I'm doing a cell optimisation run of a YAG (Y3Al5O12) crystal. I wonder
>>>> about the meaning of the tags EXTERNAL_PRESSURE and PRESSURE_TOLERANCE in
>>>> the CELL_OPT section of the input. The default values are both 100 bar.
>>>> Here are the few points I don't understand,
>>>>
>>>> 1. If the cell optimisation run is targeted at the input
>>>> EXTERNAL_PRESSURE, shouldn't the default PRESSURE_TOLERANCE be given a much
>>>> smaller value, like 5.0 or 1.0 bar?
>>>>
>>>> 2. Why 100 bar? 1 atm = 1.013 bar sounds more reasonable.
>>>>
>>>> 3. My simple understanding of cell optimisation is to find the minimum
>>>> point of the energy-volume (E-V) curve. Then what's the role of external
>>>> pressure?
>>>>
>>>> Here is my input file.
>>>>
>>>> &GLOBAL
>>>> project pristine-opt
>>>> run_type CELL_OPT
>>>> print_level MEDIUM
>>>> &END GLOBAL
>>>>
>>>> &FORCE_EVAL
>>>> METHOD QS
>>>>
>>>> &SUBSYS
>>>> &CELL
>>>> ABC 12.0003 12.0003 12.0003
>>>> PERIODIC XYZ
>>>> MULTIPLE_UNIT_CELL 1 1 1
>>>> SYMMETRY CUBIC
>>>> &END CELL
>>>>
>>>> &TOPOLOGY
>>>> MULTIPLE_UNIT_CELL 1 1 1
>>>> COORD_FILE_FORMAT XYZ
>>>> COORD_FILE_NAME yag_from_cif_conven_unit.xyz
>>>> &END TOPOLOGY
>>>>
>>>> &KIND Y
>>>> ELEMENT Y
>>>> BASIS_SET DZV-GTH-PADE
>>>> POTENTIAL GTH-PBE-q11
>>>> &END KIND
>>>>
>>>>
>>>> &KIND Al
>>>> ELEMENT Al
>>>> BASIS_SET DZVP-MOLOPT-SR-GTH
>>>> POTENTIAL GTH-PBE-q3
>>>> &END KIND
>>>>
>>>> &KIND O
>>>> ELEMENT O
>>>> BASIS_SET DZVP-GTH-PBE
>>>> POTENTIAL GTH-PBE-q6
>>>> &END KIND
>>>>
>>>> &KIND Ce
>>>> ELEMENT Ce
>>>> BASIS_SET DZVP-MOLOPT-SR-GTH-q12
>>>> POTENTIAL GTH-PBE-q12
>>>> &END KIND
>>>>
>>>> &KIND Yb
>>>> ELEMENT Yb
>>>> BASIS_SET DZVP-MOLOPT-SR-GTH-q24
>>>> POTENTIAL GTH-PBE-q24
>>>> &END KIND
>>>>
>>>> &END SUBSYS
>>>>
>>>> &DFT
>>>> BASIS_SET_FILE_NAME BASIS_SET_YAG
>>>> POTENTIAL_FILE_NAME POTENTIAL_YAG
>>>>
>>>> &MGRID
>>>> NGRIDS 4
>>>> CUTOFF 600
>>>> REL_CUTOFF 60
>>>> &END MGRID
>>>>
>>>> &QS
>>>> EPS_DEFAULT 1.0E-12
>>>> &END QS
>>>>
>>>> &POISSON
>>>> PERIODIC XYZ
>>>> &END POISSON
>>>>
>>>> &SCF
>>>> SCF_GUESS ATOMIC
>>>> EPS_SCF 5.0E-7
>>>> MAX_SCF 200
>>>>
>>>> CHOLESKY INVERSE
>>>>
>>>> &OT ON
>>>> MINIMIZER DIIS
>>>> &END OT
>>>> #&DIAGONALIZATION
>>>> # ALGORITHM STANDARD
>>>> #&END DIAGONALIZATION
>>>>
>>>> # ADDED_MOS 30
>>>> #
>>>> # &SMEAR ON
>>>> # METHOD FERMI_DIRAC
>>>> # ELECTRONIC_TEMPERATURE [K] 300
>>>> #&END SMEAR
>>>>
>>>> # &MIXING
>>>> # METHOD BROYDEN_MIXING
>>>> # ALPHA 0.4
>>>> # BETA 0.5
>>>> # NBROYDEN 8
>>>> # &END MIXING
>>>> &END SCF
>>>>
>>>> &XC
>>>> &XC_FUNCTIONAL PBE
>>>> &END XC_FUNCTIONAL
>>>> &END XC
>>>>
>>>> &KPOINTS
>>>> EPS_GEO 1.0E-5
>>>> SCHEME MONKHORST 3 3 3
>>>> &END KPOINTS
>>>> &END DFT
>>>>
>>>> &PRINT
>>>> &TOTAL_NUMBERS ON
>>>> &END TOTAL_NUMBERS
>>>> &END PRINT
>>>>
>>>> STRESS_TENSOR ANALYTICAL
>>>> &END FORCE_EVAL
>>>>
>>>> &MOTION
>>>> &GEO_OPT
>>>> OPTIMIZER LBFGS
>>>> TYPE MINIMIZATION
>>>> MAX_DR 5.0E-4
>>>> MAX_FORCE 5.0E-4
>>>> RMS_DR 5.0E-4
>>>> RMS_FORCE 5.0E-4
>>>> MAX_ITER 500
>>>> &END GEO_OPT
>>>>
>>>> &CELL_OPT
>>>> TYPE DIRECT_CELL_OPT
>>>> OPTIMIZER LBFGS
>>>> KEEP_SYMMETRY
>>>> MAX_DR 5.0E-4
>>>> MAX_FORCE 1.0E-4
>>>> RMS_DR 5.0E-4
>>>> RMS_FORCE 5.0E-4
>>>> # defaults for p and delta p [bar]
>>>> EXTERNAL_PRESSURE 100.0 0.0 0.0 0.0 100.0 0.0 0.0 0.0 100.0
>>>> PRESSURE_TOLERANCE 100.0
>>>> &END CELL_OPT
>>>> &END MOTION
>>>>
>>>>
>>>>
>>>>
>>>> Thank you,
>>>> Huaiyang Sun
>>>>
>>>>
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