Conserved quantity changed in AIMD when do restart

jtyan...@gmail.com

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Dec 26, 2020, 2:24:51 AM12/26/20

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Hi cp2k groups,

In *.ener file, I found the conserved quantity changed in AIMD from -5250.647211377 to -5250.077282796 when restart, and before restart, it's value fluctuated around -5250.647*. Could anyone tell me if it's normal or I did something wrong?

I made the restart in a way changing the *.restart directly as my new input, does it matter to my conserved quantity change?

Best regards,

J.T Yang

Lucas Lodeiro

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Dec 26, 2020, 12:17:17 PM12/26/20

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Hello Yang,

It seems you are running MD in NVT or NPT ensembles, typically when you restart an AIMD the conserved quantity does not change, but maybe you are restarting the thermostat or the barostat, or maybe you define the energy of them by hand in the input... but without more information is difficult.

Regards

Lucas Lodeiro

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jtyan...@gmail.com

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Dec 30, 2020, 3:10:24 AM12/30/20

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Hi Lodeiro,

Yes, I'm running the NVT AIMD with CSVR thermostat. I retest the restart by:

1) run a few steps of MD,

2) only change the md steps in the job-1.restart file

3) run it as a new cp2k input.

At first 20 steps I restart twice, the conserved quantity in job-1.ener didn't change much, so I kept going, thought maybe something wrong in previous results, but now I find it again!

job-1.ener posted also, I did restart after the 10, 20, and 5020 steps.

Best regards,

J.T Yang

job-1.ener:

# Step Nr. Time[fs] Kin.[a.u.] Temp[K] Pot.[a.u.] Cons Qty[a.u.] UsedTime[s]

0 0.000000 1.032460972 1050.000000000 -5252.270968874 -5251.236845323 0.000000000

1 2.000000 1.024169045 1041.567212816 -5252.262779703 -5251.236783073 549.103385597

2 4.000000 1.000225683 1017.217110463 -5252.238865354 -5251.236649738 75.174283445

3 6.000000 0.962585755 978.937770912 -5252.201197068 -5251.236464219 75.276107159

4 8.000000 0.914139020 929.668042256 -5252.152678756 -5251.236242883 80.904220160

5 10.000000 0.858349805 872.931103351 -5252.096800812 -5251.236013521 81.651709082

6 12.000000 0.798817071 812.387051503 -5252.037189382 -5251.236577364 159.194752857

7 14.000000 0.738788139 751.338371673 -5251.977118187 -5251.236413665 91.375151295

8 16.000000 0.680804621 692.369853226 -5251.919140037 -5251.236308521 74.983826838

9 18.000000 0.626572804 637.216768321 -5251.864949209 -5251.236249504 80.199529896

10 20.000000 0.577060761 586.863634428 -5251.815498133 -5251.236220285 80.784068426

12 24.000000 0.493853772 502.243159679 -5251.732424590 -5251.236740696 32.858954906

14 28.000000 0.432695037 440.045484111 -5251.671400687 -5251.236738308 27.433015823

16 32.000000 0.393161626 399.840496442 -5251.632027100 -5251.236783473 27.735265017

18 36.000000 0.372419740 378.746255003 -5251.611458500 -5251.236857986 27.595964909

20 40.000000 0.366530714 372.757188783 -5251.605688750 -5251.236889422 27.560681105

22 44.000000 0.374105358 380.460508298 -5251.613310180 -5251.236855805 30.051438093

24 48.000000 0.396871757 403.613653710 -5251.636163434 -5251.236866827 30.245694876

26 52.000000 0.433394501 440.756831162 -5251.672931132 -5251.237038189 30.459151983

28 56.000000 0.473083704 481.120257471 -5251.712966043 -5251.237311773 30.349794149

30 60.000000 0.499645958 508.133741041 -5251.739800557 -5251.237514914 24.879560947

...

2500 5000.000000 0.977387883 993.991351782 -5251.121072480 -5251.235846203 31.155438900

2502 5004.000000 0.968080556 984.525915236 -5251.110987627 -5251.235803922 30.739439011

2504 5008.000000 0.967181215 983.611296835 -5251.109342243 -5251.235789834 30.852909803

2506 5012.000000 0.975180129 991.746093257 -5251.116656932 -5251.235841020 30.885576010

2508 5016.000000 0.988735531 1005.531768656 -5251.129541711 -5251.235914681 31.094295979

2510 5020.000000 1.003008497 1020.047198254 -5251.143101180 -5251.235956305 33.428025007

2512 5024.000000 1.014004705 1031.230205110 -5251.154416285 -5250.138425674 39.710912943

2514 5028.000000 1.023493085 1040.879769453 -5251.164161323 -5250.138356331 31.283514023

2516 5032.000000 1.035539764 1053.131093440 -5251.176477561 -5250.138296787 28.679327965

2518 5036.000000 1.053082568 1070.971906866 -5251.194412595 -5250.138355038 31.430841208

2520 5040.000000 1.072657780 1090.879654295 -5251.214447055 -5250.138473518 31.346939087

2522 5044.000000 1.087218443 1105.687668194 -5251.229417942 -5250.138536010 31.335617065

2524 5048.000000 1.092733336 1111.296246422 -5251.235274793 -5250.138525122 31.344972849

2526 5052.000000 1.089722800 1108.234568200 -5251.232575896 -5250.138481510 31.441764832

jtyan...@gmail.com

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Dec 30, 2020, 8:54:53 PM12/30/20

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Update, I tried use block EXT_RESTART:

add

&ext_restart

restart_file_name job-1.restart

&end ext_restart

to first run file head, same problem!

fabia...@gmail.com

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Jan 7, 2021, 12:42:17 PM1/7/21

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Dear J.T Yang,

I posted a longer answer here:

https://mattermodeling.stackexchange.com/questions/4064/cp2k-conserved-quantity-changed-when-restart-nvt-md

In short: you use the Nose Hoover thermostat because you did not define TYPE CSVR. But because no &NOSE section is defined in the input the restart file does not contain information about the Nose Hoover thermostat. This causes the thermostat to be reinitialized when the MD is continued and the "conserved quantity" is not conserved.