From: Cesar Luis Avila (cavila_at_fbqf.unt.edu.ar)
Date: Tue May 29 2007 - 09:53:31 CDT
The restart files, time step and seed are exactly the same as those from 
previous runs. Indeed the shift appears in the middle of the run, not at 
restart. "1ns" takes a week on my small cluster :(.  Since it is the 
first time that i see something like this, I do not know if this shift 
might be regarded as normal, or if it should be recalculated.
Attached I send you a snapshot of the TOTAL energy plot vs timestep. 
Please ask for any other graph or data needed to work this out.
Thanks for your help.
Cesar
hl332_at_drexel.edu escribió:
>  Check again and make sure, you did take the right restart files, right time step from end of previous run and right seed. If still not convinced, try restarting run for this "1ns" period again which wont take too long. Thats what I would do in case unable to find reason of why this shift?
>
> Harish
> -------------------------------------------------
> Harish Vashisth (Ph.D Candidate)
> CAT-361,Chemical & Biological Engg.
> Drexel University, Philadelphia, PA
> office: 215-895-5823
>
> ----- Original Message -----
> From: Cesar Luis Avila <cavila_at_fbqf.unt.edu.ar>
> Date: Monday, May 28, 2007 7:26 pm
> Subject: Re: namd-l: Energy shift during simulation
>
>   
>> I have the TOTAL energy fluctuating around a given value for nearly 
>> 10 
>> ns. At 10.5 ns I suddenly observe a shift in the energy as well as 
>> in 
>> the temperature and then it returns to previous values at 11 ns.
>> I am aware that the energy won't be fixed, but this sudden shift 
>> seems 
>> suspicious.
>>
>> hl332_at_drexel.edu escribió:
>>     
>>> Hi,
>>>     You have been using an NPT ensemble run where  number of 
>>>       
>> particles, pressure, temperature should stay constant and Energy is 
>> variable. I dont see what the problem is really? If you want to 
>> make energy constant, do an NVE run instead.
>>     
>>> I hope it helps.
>>>
>>> Harish
>>>
>>>
>>> -------------------------------------------------
>>> Harish Vashisth (Ph.D Candidate)
>>> CAT-361,Chemical & Biological Engg.
>>> Drexel University, Philadelphia, PA
>>> office: 215-895-5823
>>>
>>> ----- Original Message -----
>>> From: Cesar Luis Avila <cavila_at_fbqf.unt.edu.ar>
>>> Date: Monday, May 28, 2007 5:21 pm
>>> Subject: namd-l: Energy shift during simulation
>>>
>>>   
>>>       
>>>> Dear all,
>>>> I am conducting a simulation of a protein membrane system. I 
>>>>         
>> have 
>>     
>>>> decided to split the simulation on 1 ns step, saving energies 
>>>>         
>> and 
>>     
>>>> coordinates every 10 ps. I am using NPT ensemble (Langevin) 
>>>>         
>> using 
>>     
>>>> ConstantRatio.
>>>>
>>>> After 10 ns I noticed a shift on the TOTAL energy (contributed 
>>>> mainly by 
>>>> ANGLE + DIHEDRAL + KINETIC ) and TEMP around step 10420000. The 
>>>> ENERGY 
>>>> returns to previous values only when I restarted the simulation 
>>>>         
>> on 
>>     
>>>> step 
>>>> 11000000.
>>>>
>>>> Any clue on what might be happening? And what should I do? 
>>>>         
>> Discard 
>>     
>>>> this 
>>>> data and resume from step 100000?
>>>>
>>>> ETITLE:      TS           BOND          ANGLE          DIHED     
>>>>         
>>   
>>     
>>>>  
>>>> IMPRP               ELECT            VDW       BOUNDARY          
>>>>         
>>>> MISC        KINETIC               TOTAL           TEMP         
>>>> TOTAL2         TOTAL3        TEMPAVG            PRESSURE      
>>>> GPRESSURE         VOLUME       PRESSAVG      GPRESSAVG
>>>>
>>>> ENERGY: 10300000     63609.6505     64570.8779     16318.2654    
>>>>         
>>   
>>     
>>>> 917.3728        -591430.8385     29709.2435         0.0000       
>>>>         
>>  
>>     
>>>> 0.0000    185866.1012        -230439.3271       324.1665   
>>>> -228060.7668   -227954.7134       325.0299           1450.5216   
>>>>         
>>   
>>     
>>>> -197.6874   1853385.2552         0.0403        -0.1946
>>>> ENERGY: 10310000     63800.1438     64113.9093     16373.1687    
>>>>         
>>   
>>     
>>>> 904.6770        -591969.1599     29918.4770         0.0000       
>>>>         
>>  
>>     
>>>> 0.0000    185952.7454        -230906.0388       324.3176   
>>>> -228503.6012   -228511.4695       325.0235           1680.2639   
>>>>         
>>   
>>     
>>>> -79.4904   1850572.7046         1.5285         1.8823
>>>> ENERGY: 10320000     63731.1341     64542.3796     16312.3888    
>>>>         
>>   
>>     
>>>> 928.3302        -592395.1306     29677.3780         0.0000       
>>>>         
>>  
>>     
>>>> 0.0000    186575.9104        -230627.6093       325.4044   
>>>> -228229.7364   -228220.0970       325.0447           1684.6130   
>>>>         
>>   
>>     
>>>>  
>>>> 19.3906   1847303.2782         1.0025         1.0650
>>>> ENERGY: 10330000     63398.1087     64145.3713     16404.7305    
>>>>         
>>   
>>     
>>>> 931.7793        -592090.6118     29817.9364         0.0000       
>>>>         
>>  
>>     
>>>> 0.0000    186508.3964        -230884.2891       325.2867   
>>>> -228503.4313   -228433.2293       325.0251           1733.0630   
>>>>         
>>   
>>     
>>>> -189.9830   1848356.1095         1.7627         1.7452
>>>> ENERGY: 10340000     63918.9096     64585.9508     16418.7835    
>>>>         
>>   
>>     
>>>> 875.5280        -592955.6394     30736.1507         0.0000       
>>>>         
>>  
>>     
>>>> 0.0000    186098.4177        -230321.8992       324.5717   
>>>> -227926.7176   -227884.4924       325.0322           2101.0069   
>>>>         
>>   
>>     
>>>> 229.6281   1851654.4936         1.4528         1.6165
>>>> ENERGY: 10350000     63567.5613     64759.4829     16217.4356    
>>>>         
>>   
>>     
>>>> 889.1424        -591727.6567     29738.3133         0.0000       
>>>>         
>>  
>>     
>>>> 0.0000    186278.3960        -230277.3253       324.8856   
>>>> -227879.1186   -227873.0291       325.0988           1914.3131   
>>>>         
>>   
>>     
>>>>  
>>>> 95.1531   1850918.0950         0.0627         0.0207
>>>> ENERGY: 10360000     63901.9471     64255.2030     16386.2734    
>>>>         
>>   
>>     
>>>> 925.6849        -591209.3716     29854.6413         0.0000       
>>>>         
>>  
>>     
>>>> 0.0000    186425.9808        -229459.6412       325.1430   
>>>> -227064.1050   -227027.4999       325.0474           1777.5875   
>>>>         
>>   
>>     
>>>> -50.7852   1852831.2636        -0.3381        -1.0205
>>>> ENERGY: 10370000     63339.7705     64689.0525     16414.3804    
>>>>         
>>   
>>     
>>>> 909.3640        -592508.3969     30184.9106         0.0000       
>>>>         
>>  
>>     
>>>> 0.0000    186440.8797        -230530.0392       325.1689   
>>>> -228121.7505   -228155.9220       325.0388           1907.0434   
>>>>         
>>   
>>     
>>>>  
>>>> -4.1627   1850041.9880         0.2329         0.4851
>>>> ENERGY: 10380000     63178.1926     64696.6552     16347.7512    
>>>>         
>>   
>>     
>>>> 939.7491        -591640.3336     29881.3682         0.0000       
>>>>         
>>  
>>     
>>>> 0.0000    186839.2189        -229757.3984       325.8637   
>>>> -227369.7937   -227323.4315       325.0963           1977.5063   
>>>>         
>>   
>>     
>>>> -30.4046   1847092.7663        -0.5036        -0.7161
>>>> ENERGY: 10390000     63996.0173     64648.3814     16396.8117    
>>>>         
>>   
>>     
>>>> 926.3078        -592074.6561     30166.7425         0.0000       
>>>>         
>>  
>>     
>>>> 0.0000    185975.2774        -229965.1180       324.3569   
>>>> -227577.4960   -227516.0743       325.0763           1905.7479   
>>>>         
>>   
>>     
>>>>  
>>>> 93.6511   1849921.5963         0.9937         0.8142
>>>> ENERGY: 10400000     63853.9013     64070.7798     16331.7615    
>>>>         
>>   
>>     
>>>> 924.0796        -591846.8154     30145.9941         0.0000       
>>>>         
>>  
>>     
>>>> 0.0000    186696.5286        -229823.7704       325.6148   
>>>> -227428.0385   -227387.5511       325.0728           1747.0664   
>>>>         
>>   
>>     
>>>>  
>>>> 28.2482   1854110.4170        -2.8355        -2.2988
>>>> ENERGY: 10410000     63488.3269     64647.3090     16436.2537    
>>>>         
>>   
>>     
>>>> 921.6758        -591827.7839     30088.6061         0.0000       
>>>>         
>>  
>>     
>>>> 0.0000    186010.3933        -230235.2190       324.4181   
>>>> -227840.1402   -227818.6152       324.9854           1820.6818   
>>>>         
>>   
>>     
>>>> -27.9187   1849769.2296        -0.4637         0.1865
>>>> ENERGY: 10420000     63778.0021     64998.8286     16599.4685    
>>>>         
>>   
>>     
>>>> 924.7329        -591598.4523     29967.0566         0.0000       
>>>>         
>>  
>>     
>>>> 0.0000    187299.0044        -228031.3592       326.6656   
>>>> -225627.9244   -225593.2967       326.2422           1803.6118   
>>>>         
>>   
>>     
>>>> -110.9619   1850160.6637         1.7969         1.8479
>>>> ENERGY: 10430000     64008.6044     65556.9899     16769.9379    
>>>>         
>>   
>>     
>>>> 927.1032        -591933.4968     30377.2170         0.0000       
>>>>         
>>  
>>     
>>>> 0.0000    187947.0020        -226346.6424       327.7957   
>>>> -223936.7567   -223933.8235       327.1259           1956.7638   
>>>>         
>>   
>>     
>>>> -35.1648   1851146.0456         2.3698         2.3364
>>>> ENERGY: 10440000     63967.3836     65310.1901     16548.3853    
>>>>         
>>   
>>     
>>>> 876.5539        -592244.7863     30355.2727         0.0000       
>>>>         
>>  
>>     
>>>> 0.0000    186854.5382        -228332.4625       325.8904   
>>>> -225906.7514   -225967.7844       327.1985           1851.4702   
>>>>         
>>   
>>     
>>>>  
>>>> 67.3314   1851539.2548         0.1672         0.1645
>>>> ENERGY: 10450000     64043.4908     65300.3392     16628.0304    
>>>>         
>>   
>>     
>>>> 911.8170        -591921.1518     30147.7787         0.0000       
>>>>         
>>  
>>     
>>>> 0.0000    187477.2339        -227412.4619       326.9764   
>>>> -224980.4613   -225036.7252       327.0621           1954.6794   
>>>>         
>>   
>>     
>>>>  
>>>> 81.8472   1851476.2295         2.8552         2.8622
>>>> ENERGY: 10460000     63831.1771     65127.2486     16578.3829    
>>>>         
>>   
>>     
>>>> 890.9648        -592695.3985     30367.5321         0.0000       
>>>>         
>>  
>>     
>>>> 0.0000    187176.1816        -228723.9114       326.4514   
>>>> -226330.8714   -226248.8746       326.9795           1969.0847   
>>>>         
>>   
>>     
>>>>  
>>>> 19.2833   1849709.6477         1.2673         1.2717
>>>> ENERGY: 10470000     63931.1120     65583.6408     16413.7982    
>>>>         
>>   
>>     
>>>> 941.7629        -592226.2966     30156.8957         0.0000       
>>>>         
>>  
>>     
>>>> 0.0000    188021.6487        -227177.4382       327.9259   
>>>> -224798.4522   -224667.5801       327.0829           1832.2226   
>>>>         
>>   
>>     
>>>> -19.2946   1851583.0035         0.2917         0.6956
>>>> ENERGY: 10480000     63687.5879     65078.5959     16564.2646    
>>>>         
>>   
>>     
>>>> 918.0522        -591566.5008     30384.6587         0.0000       
>>>>         
>>  
>>     
>>>> 0.0000    186963.3201        -227970.0215       326.0801   
>>>> -225542.0302   -225593.2482       326.8874           1800.6804   
>>>>         
>>   
>>     
>>>> -23.3607   1852368.2878        -2.5195        -2.0388
>>>> ENERGY: 10490000     64074.4914     64860.3827     16618.2216    
>>>>         
>>   
>>     
>>>> 921.0558        -593361.4120     30875.6371         0.0000       
>>>>         
>>  
>>     
>>>> 0.0000    187303.2910        -228708.3325       326.6731   
>>>> -226298.1552   -226282.6418       326.8636           1730.4118   
>>>>         
>>   
>>     
>>>> -49.5610   1852771.6838        -1.5235        -1.2356
>>>> ENERGY: 10500000     63640.9008     65012.5143     16530.3874    
>>>>         
>>   
>>     
>>>> 916.0746        -592011.6342     30193.3293         0.0000       
>>>>         
>>  
>>     
>>>> 0.0000    187557.1582        -228161.2696       327.1158   
>>>> -225738.1892   -225772.5514       326.9812           2056.2349   
>>>>         
>>   
>>     
>>>>  
>>>> 52.2942   1851763.0133         0.7401         0.4435
>>>>
>>>>
>>>>     
>>>>         
>>>   
>>>       
>>     
>
>
>   
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