Temperature control problem (MD)

emerson p l

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Jun 13, 2025, 12:38:08 PM6/13/25

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Dear CP2K community,

I was running an MD simulation (using the "cp2k-md.inp" file) and noticed a possible issue.

Two energy files are being generated. One is called "cp2k-md-1.ener", which I believe is the main one, and another called "cp2k-md-1.bener", which I believe is related to the barostat.

The simulation I'm running is at 450 K. The issue is that in the "cp2k-md-1.bener" file, the temperature seems to be controlled (i.e., it fluctuates around 450 K). However, in the "cp2k-md-1.ener" file, it starts at 450 K but decreases and seems to fluctuate around ~250 K.

Could there be something wrong with my script? Or did I misunderstand what each file represents?

Thank you in advance.

Best,

Emerson

cp2k-md-1.bener

cp2k-md-1.ener

cp2k-md.inp

Michela Benazzi

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Jun 13, 2025, 4:19:04 PM6/13/25

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Can you give us the xyz file?

I was initially going to suggest lowering the TIMECON under thermostat, but I am not confident that would be a way to see faster equilibration. I would also run it for a little longer before making conclusions - I will still let the experts speak!

Michela

emerson p l

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Jun 17, 2025, 7:03:28 AM6/17/25

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Can someone kindly help me with this question?

Best,

Emerson

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Marcella Iannuzzi

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Jun 17, 2025, 7:13:24 AM6/17/25

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Hi Emerson,

There is something going wrong in the simulation you posted.

The same step has been printed out multiple times (see the section of the energy file below).

Only 32 fs have been completed in total, which is not enough to determine whether the thermostat

is going to bring the system to the desired temperature.

Regards

Marcella

1 0.500000 0.089569980 438.510524146 -562.901811460 -562.804542284 2801.022729389

1 0.500000 0.089569980 438.510524146 -562.901811460 -562.804542284 2801.072794579

1 0.500000 0.089569980 438.510524146 -562.901811460 -562.804542284 2801.889037296

1 0.500000 0.089569980 438.510524146 -562.901811460 -562.804542284 2802.841863686

1 0.500000 0.089569980 438.510524146 -562.901811460 -562.804542284 2803.706763471

1 0.500000 0.089569980 438.510524146 -562.901811460 -562.804542284 2803.376106928

1 0.500000 0.089569980 438.510524146 -562.901811460 -562.804542284 2803.623549463

1 0.500000 0.089569980 438.510524146 -562.901811460 -562.804542284 2803.801165718

1 0.500000 0.089569980 438.510524146 -562.901811460 -562.804542284 2804.811095665

1 0.500000 0.089569980 438.510524146 -562.901811460 -562.804542284 2804.470775342

1 0.500000 0.089569980 438.510524146 -562.901811460 -562.804542284 2804.514003073

1 0.500000 0.089569980 438.510524146 -562.901811460 -562.804542284 2805.691727090

1 0.500000 0.089569980 438.510524146 -562.901811460 -562.804542284 2805.470237689

1 0.500000 0.089569980 438.510524146 -562.901811460 -562.804542284 2805.698754238

1 0.500000 0.089569980 438.510524146 -562.901811460 -562.804542284 2805.415502365

1 0.500000 0.089569980 438.510524146 -562.901811460 -562.804542284 2805.995257901

1 0.500000 0.089569980 438.510524146 -562.901811460 -562.804542284 2806.185929011

1 0.500000 0.089569980 438.510524146 -562.901811460 -562.804542284 2806.067843263

1 0.500000 0.089569980 438.510524146 -562.901811460 -562.804542284 2806.090844038

1 0.500000 0.089569980 438.510524146 -562.901811460 -562.804542284 2806.919571166

1 0.500000 0.089569980 438.510524146 -562.901811460 -562.804542284 2806.266657210

1 0.500000 0.089569980 438.510524146 -562.901811460 -562.804542284 2806.083707575

1 0.500000 0.089569980 438.510524146 -562.901811460 -562.804542284 2806.223140005

1 0.500000 0.089569980 438.510524146 -562.901811460 -562.804542284 2806.832137327

1 0.500000 0.089569980 438.510524146 -562.901811460 -562.804542284 2806.291292903

1 0.500000 0.089569980 438.510524146 -562.901811460 -562.804542284 2806.475402954

1 0.500000 0.089569980 438.510524146 -562.901811460 -562.804542284 2806.732517401

1 0.500000 0.089569980 438.510524146 -562.901811460 -562.804542284 2806.538222783

1 0.500000 0.089569980 438.510524146 -562.901811460 -562.804542284 2806.800985989

1 0.500000 0.089569980 438.510524146 -562.901811460 -562.804542284 2806.777102191

1 0.500000 0.089569980 438.510524146 -562.901811460 -562.804542284 2806.830183923

1 0.500000 0.089569980 438.510524146 -562.901811460 -562.804542284 2807.005762795

1 0.500000 0.089569980 438.510524146 -562.901811460 -562.804542284 2807.926197457

1 0.500000 0.089569980 438.510524146 -562.901811460 -562.804542284 2807.359545282

1 0.500000 0.089569980 438.510524146 -562.901811460 -562.804542284 2807.385383636

1 0.500000 0.089569980 438.510524146 -562.901811460 -562.804542284 2807.375495759

1 0.500000 0.089569980 438.510524146 -562.901811460 -562.804542284 2807.890949295

1 0.500000 0.089569980 438.510524146 -562.901811460 -562.804542284 2807.891639697

1 0.500000 0.089569980 438.510524146 -562.901811460 -562.804542284 2808.025214566

1 0.500000 0.089569980 438.510524146 -562.901811460 -562.804542284 2808.310062688

1 0.500000 0.089569980 438.510524146 -562.901811460 -562.804542284 2808.945081238

1 0.500000 0.089569980 438.510524146 -562.901811460 -562.804542284 2809.972221775

1 0.500000 0.089569980 438.510524146 -562.901811460 -562.804542284 2810.133391557

1 0.500000 0.089569980 438.510524146 -562.901811460 -562.804542284 2810.428579383

1 0.500000 0.089569980 438.510524146 -562.901811460 -562.804542284 2810.773275483

1 0.500000 0.089569980 438.510524146 -562.901811460 -562.804542284 2811.091263300

1 0.500000 0.089569980 438.510524146 -562.901811460 -562.804542284 2811.309236270

emerson p l

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Jun 26, 2025, 2:53:19 PM6/26/25

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Many thanks everyone for the comments.

Michela, I reduced TIMECON and achieved equilibration. Thank you very much.

I didn’t reply sooner because somehow the message went to spam.

Best,

Emerson

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Michela Benazzi

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Jun 27, 2025, 12:40:09 PM6/27/25

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No problem, Emerson! I am glad it worked.

Michela

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