drastic change in pressure on changing smoothing
Matt W
MattWa... at gmail.com
Fri Dec 4 12:01:48 UTC 2015
Hi,
running NPT calculations are not straightforward. The stress tensor needs
to be reasonably converged wrt the cutoff to get reliable results. The
cutoff to converge the stress tensor might be much larger than for reliable
forces.
Matt
On Thursday, December 3, 2015 at 5:00:18 PM UTC, Bernd Ensing wrote:
>
>
> Dear cp2k developers,
>
> Is it known whether there is a bug in the calculation of the pressure
> tensor when using XC_SMOOTH_RHO NN10?
> Using this smoothing option results in very negative pressures for a
> typical system containing 64 water molecules (see message below of Ambuj
> Tiwari).
> Does this strange behaviour also affect the forces on the atoms in general?
>
> Many thanks in advance for your comments.
> best wishes,
>
> Bernd Ensing
>
>
>
> Op woensdag 25 november 2015 13:49:36 UTC+1 schreef Ambuj Tiwari:
>>
>> Dear All,
>> I am running a NVT MD simulation on bulkwater(64 water molecules) . The
>> problem is related to pressure calculation.
>> I was calculating the pressure for the system and found highly negative
>> values(in order of -25000) and then I switched all the parameters one by
>> one and eventually found out that on changing smoothing from XC_SMOOTH_RHO
>> NN10 to USE_FINER_GRID it came down to less negative values(-5000). Is this
>> some kind of bug in the program or more fundamental problem.
>>
>> I am attaching the input file and bottom of .ener .stress file here.
>>
>> Regards,
>> Ambuj
>>
>>
>> *'input file 1'*
>>
>> <https://en.wikipedia.org/wiki/Car%E2%80%93Parrinello_molecular_dynamics#cite_note-3>
>> &XC
>> &XC_FUNCTIONAL BLYP
>> &END XC_FUNCTIONAL
>> &VDW_POTENTIAL
>> DISPERSION_FUNCTIONAL PAIR_POTENTIAL
>> &PAIR_POTENTIAL
>> TYPE DFTD3
>> PARAMETER_FILE_NAME /home/ensing/BASIS_SET/dftd3.dat
>> REFERENCE_FUNCTIONAL BLYP
>> &END PAIR_POTENTIAL
>> &END VDW_POTENTIAL
>> &XC_GRID
>>
>> * XC_SMOOTH_RHO NN10 XC_DERIV SPLINE2_SMOOTH*
>> &END XC_GRID
>> &END XC
>>
>> *'input file 2'*
>>
>>
>> &XC
>> &XC_FUNCTIONAL BLYP
>> &END XC_FUNCTIONAL
>> &VDW_POTENTIAL
>> DISPERSION_FUNCTIONAL PAIR_POTENTIAL
>> &PAIR_POTENTIAL
>> TYPE DFTD3
>> PARAMETER_FILE_NAME /home/ensing/BASIS_SET/dftd3.dat
>> REFERENCE_FUNCTIONAL BLYP
>> &END PAIR_POTENTIAL
>> &END VDW_POTENTIAL
>> &XC_GRID
>> * USE_FINER_GRID *
>> &END XC_GRID
>> &END XC
>>
>>
>> *'*.ener 1'*
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>> * 163298 81649.000000 0.295424393
>> 325.610938118 -1101.039478079 -1100.781654417
>> 22.112000000 163299 81649.500000 0.294462120
>> 324.550339188 -1101.039370784 -1100.781669902
>> 22.078000000 163300 81650.000000 0.294961268
>> 325.100490947 -1101.040473093 -1100.781725319
>> 25.159000000 163301 81650.500000 0.296162908
>> 326.424914893 -1101.042161493 -1100.781750771
>> 22.115700000 163302 81651.000000 0.298814382
>> 329.347317264 -1101.044236790 -1100.781694623
>> 22.139200000 163303 81651.500000 0.301128239
>> 331.897603891 -1101.047561646 -1100.781602129
>> 24.739700000 163304 81652.000000 0.307044448
>> 338.418332848 -1101.053434140 -1100.781587012
>> 24.682400000 163305 81652.500000 0.316425516
>> 348.757961573 -1101.061982016 -1100.781699977
>> 22.044200000 163306 81653.000000 0.327014965
>> 360.429442967 -1101.071396202 -1100.781872287 22.101900000*
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>> *'*.ener 2' 91 45.500000 0.316250053
>> 348.564569099 -1102.663360533 -1102.332927916
>> 65.288200000 92 46.000000 0.315037265
>> 347.227857880 -1102.661696314 -1102.332913105
>> 65.190400000 93 46.500000 0.314019534
>> 346.106135819 -1102.660798344 -1102.332914267
>> 65.276700000 94 47.000000 0.314010873
>> 346.096588928 -1102.660760313 -1102.332937169
>> 65.315200000 95 47.500000 0.315000947
>> 347.187829574 -1102.661384548 -1102.332972600
>> 65.163300000 96 48.000000 0.315886554
>> 348.163928325 -1102.662099658 -1102.333054612
>> 65.248800000 97 48.500000 0.315298803
>> 347.516120600 -1102.661788013 -1102.333132240
>> 65.120100000 98 49.000000 0.313543746
>> 345.581730970 -1102.659461626 -1102.333136220
>> 65.202000000 99 49.500000 0.309178417
>> 340.770351269 -1102.655147713 -1102.333068024
>> 63.328600000 100 50.000000 0.304077471
>> 335.148189283 -1102.649908792 -1102.332978856
>> 64.191200000
>> '*.stress 1'*
>> 163294 81647.000 -23587.6933211956 2342.2050511699
>> -2620.1253216644 2342.2050511699 -23228.0050606190
>> 3414.1775796133 -2620.1253216644 3414.1775796133 -20169.0313283565
>> 163295 81647.500 -22389.3419955310 1849.7028598497
>> -2508.5434330934 1849.7028598497 -24356.6599768539
>> 2800.7048436858 -2508.5434330934 2800.7048436858 -22725.6161101663
>> 163296 81648.000 -21214.9735696668 1148.0699336617
>> -2218.3871712667 1148.0699336617 -25144.9624318558
>> 1975.3590510643 -2218.3871712667 1975.3590510643 -24795.3384458679
>> 163297 81648.500 -20309.0216433928 302.8654094409
>> -1803.1704603762 302.8654094409 -25394.9473522949
>> 996.8049404043 -1803.1704603762 996.8049404043 -26162.6367896449
>> 163298 81649.000 -19855.8176878975 -598.7972734722
>> -1300.5824885129 -598.7972734722 -24999.8852946563
>> -79.5868061270 -1300.5824885129 -79.5868061270 -26686.2571452786
>> 163299 81649.500 -19956.2226579495 -1461.2946422884
>> -742.0897491587 -1461.2946422884 -24019.8747323228
>> -1206.1348202948 -742.0897491587 -1206.1348202948 -26376.7375359960
>> 163300 81650.000 -20534.1679738551 -2200.5578986806
>> -164.8658164621 -2200.5578986806 -22584.1267162156
>> -2322.5467222548 -164.8658164621 -2322.5467222548 -25268.9877352706
>> 163301 81650.500 -21452.3785466678 -2746.9001879179
>> 376.2080784084 -2746.9001879179 -20951.8376784856
>> -3338.3737161118 376.2080784084 -3338.3737161118 -23492.0302819538
>>
>>
>> *'*.stress 2'*
>> 83 41.500 14620.6789775920 1631.8725215074
>> 2233.0775150043 1631.8725215074 6922.5364171994
>> 1568.9298877547 2233.0775150043 1568.9298877547 4863.0813795099
>> 84 42.000 13465.9504463874 1646.6798565162
>> 1742.3968878509 1646.6798565162 7528.7642280447
>> 1356.1689695128 1742.3968878509 1356.1689695128 3678.0979512013
>> 85 42.500 11929.6829243335 1557.1878823967
>> 1189.8285351507 1557.1878823967 7536.6702267556
>> 906.2538614813 1189.8285351507 906.2538614813 2706.1024195638
>> 86 43.000 10242.7023865733 1377.0907756499
>> 607.2431768383 1377.0907756499 6953.6306436901
>> 280.8453243292 607.2431768383 280.8453243292 2111.5249630222
>> 87 43.500 8704.9333307887 1111.3766575987
>> 27.5775490784 1111.3766575987 5939.0119410377
>> -388.5800033232 27.5775490784 -388.5800033232 2026.3208988151
>> 88 44.000 7481.3245836153 770.0630298266
>> -494.3356330308 770.0630298266 4626.9158749281
>> -951.4354212867 -494.3356330308 -951.4354212867 2390.6634657579
>> 89 44.500 6663.8847520724 360.1790480556
>> -890.4213349779 360.1790480556 3225.2634082928
>> -1279.9170414956 -890.4213349779 -1279.9170414956 3064.5349399335
>> 90 45.000 6254.7640395386 -100.7086327357
>> -1091.1835737339 -100.7086327357 1954.1849838233
>> -1309.6032354774 -1091.1835737339 -1309.6032354774 3839.7803365830
>> 91 45.500 6155.5011736691 -574.1695321638
>> -1051.6467240489 -574.1695321638 957.4978282879
>> -1053.9528084102 -1051.6467240489 -1053.9528084102 4443.4869908843
>> 92 46.000 6285.5912946027 -1016.5428590808
>> -783.4044479712 -1016.5428590808 376.4627244754
>> -574.9649194818 -783.4044479712 -574.9649194818 4722.8910330993
>> 93 46.500 6504.7623119346 -1380.8418795540
>> -361.7805767782 -1380.8418795540 216.2588001339
>> 37.9199806709 -361.7805767782 37.9199806709 4578.5854391507
>> 94 47.000 6695.7329680208 -1630.3118660115
>> 95.8727981760 -1630.3118660115 437.0880477724
>> 702.9749077441 95.8727981760 702.9749077441 4059.5915440691
>>
>>
>> Thanks in advance!
>>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.cp2k.org/archives/cp2k-user/attachments/20151204/01fc0e07/attachment.htm>
More information about the CP2K-user
mailing list