[ase-users] NPTBerendsen()

[Tristan Maxson]

I think we would need a much more complete input to help.  This could be an
error in the calculator instead for example.  I do know the NPTBerendsen
should work more or less with your input.  Please confirm an EMT run of
metal with those parameters works.

Thank you,
Tristan Maxson

On Sun, Oct 27, 2024, 11:30 AM Vitaly Vitalievich <vvchaban at gmail.com>
wrote:

> Right, regarding T. But the problem looks to be deeper. Below is what I
> found. The simulation started correctly but after the first NPT step the
> cell size got to (0,0,0).
>
>           MOPAC Job: "vvc.mop" ended normally on Oct 27, 2024, at 20:23.
>           MOPAC Job: "vvc.mop" ended normally on Oct 27, 2024, at 20:23.
> *Cell([10.0, 10.0, 10.0])*
> Error in the loop occurred. Probably the SCF procedure did not converge.
> Continuing to the next configuration.
> *Cell([0.0, 0.0, 0.0])*
> Error in the loop occurred. Probably the SCF procedure did not converge.
> Continuing to the next configuration.
> Cell([0.0, 0.0, 0.0])
> Error in the loop occurred. Probably the SCF procedure did not converge.
> Continuing to the next configuration.
>
>
> Also, the logfile -
> Time[ps]      Etot[eV]     Epot[eV]     Ekin[eV]    T[K]
> 0.0000          15.4172      15.4048       0.0123     1.0
> Time[ps]      Etot[eV]     Epot[eV]     Ekin[eV]    T[K]
> 0.0000          15.4178      15.4048       0.0130     1.1
> Time[ps]      Etot[eV]     Epot[eV]     Ekin[eV]    T[K]
> 0.0000          15.4166      15.4048       0.0117     1.0
> Time[ps]      Etot[eV]     Epot[eV]     Ekin[eV]    T[K]
> 0.0000          15.4158      15.4048       0.0109     0.9
>
>
>
>
>
> On Sun, Oct 27, 2024 at 5:59 PM Tristan Maxson <tgmaxson at gmail.com> wrote:
>
>> What does the log file say?  I believe you should set temperature as
>> temperature_K=400, there may be a unit mismatch.
>>
>> On Sun, Oct 27, 2024, 7:26 AM Vitaly Vitalievich <vvchaban at gmail.com>
>> wrote:
>>
>>> MD = NPTBerendsen(SYSTEM, 1 * units.fs, 400 * units.K, pressure=1 *
>>> units.bar, taut=100*units.fs, taup=1000*units.fs,
>>> compressibility=5e-5/units.bar)
>>>
>>> The execution terminates  after the first time step due to the SCF
>>> convergence error. However, the first SCF does converge.
>>>
>>>
>>>
>>>
>>> On Sun, Oct 27, 2024 at 4:04 PM Tristan Maxson <tgmaxson at gmail.com>
>>> wrote:
>>>
>>>> Please supply a minimum failing example for us to look at for you.
>>>>
>>>> Thank you,
>>>> Tristan Maxson
>>>>
>>>> On Sun, Oct 27, 2024, 4:37 AM Vitaly Vitalievich via ase-users <
>>>> ase-users at listserv.fysik.dtu.dk> wrote:
>>>>
>>>>> I would like to reiterate my request, please.
>>>>>
>>>>> The NPT() function of ASE appears to exhibit the same type of
>>>>> misbehavior.
>>>>>
>>>>> Thank you for your attention to this matter.
>>>>>
>>>>>
>>>>> On Sun, Oct 20, 2024 at 10:09 AM Vitaly Vitalievich <
>>>>> vvchaban at gmail.com> wrote:
>>>>>
>>>>>> Dear All -
>>>>>>
>>>>>> I would greatly appreciate getting an example of using
>>>>>>
>>>>>> NPTBerendsen()
>>>>>>
>>>>>> function, say, for a liquid water system, dt = 1fs. I have some
>>>>>> misunderstanding with the input constants / units ending with bad geometry.
>>>>>>
>>>>>> Cheers, Vitaly
>>>>>>
>>>>>> _______________________________________________
>>>>> ase-users mailing list
>>>>> ase-users at listserv.fysik.dtu.dk
>>>>> https://listserv.fysik.dtu.dk/mailman/listinfo/ase-users
>>>>>
>>>>
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