[gmx-users] umbrella sampling

Justin Lemkul jalemkul at vt.edu
Sun Feb 4 21:36:04 CET 2018



On 2/4/18 3:25 PM, Rose wrote:
> Jeah,i meant grompp :)))
> and last question, i set constraint = h-Bonds, and dt=0.002 because Of  that(since usually h-Bonds have Max frequency and.... if i assume them constraint so it's not reasonable to set dt=0.001 ) , is this assumption true?

You can always decrease dt, that's "reasonable," but it makes no sense 
and is inefficient. Without any form of constraints, you'd likely be 
limited to dt = 0.0005 in many cases.

-Justin

> Sent from my iPhone
>
>> On Feb 4, 2018, at 23:30, Justin Lemkul <jalemkul at vt.edu> wrote:
>>
>>
>>
>>> On 2/4/18 1:56 PM, Rose wrote:
>>> Thank you so much,
>>> Is it difference between using gmx tpbconv -extend  5ps OR use .gro file of last simulation as an input For new 5nS simulation?(continiuation=yes in .mdp file)
>> The only reason to invoke grompp is if you're changing something about the system. For a simple continuation use tpbconv/convert-tpr and mdrun -cpi.
>>
>> -Justin
>>
>>> Sent from my iPhone
>>>
>>>> On Feb 4, 2018, at 17:00, Justin Lemkul <jalemkul at vt.edu> wrote:
>>>>
>>>>
>>>>
>>>>> On 2/2/18 10:44 AM, Rose wrote:
>>>>>
>>>>> Sent from my iPhone
>>>>>
>>>>>> On Feb 2, 2018, at 19:01, Justin Lemkul <jalemkul at vt.edu> wrote:
>>>>>>
>>>>>>
>>>>>>
>>>>>>> On 2/2/18 8:43 AM, rose rahmani wrote:
>>>>>>>   Hi, i'm doing umbrella sampling.(pulling AA toward nanosheet).and 4nS
>>>>>>> simulation for each window.
>>>>>>>
>>>>>>>>> g_energy -f umbrella0.edr -o out.xvg
>>>>>>>   1  Bond             2  Angle            3  Proper-Dih.      4
>>>>>>> Improper-Dih.
>>>>>>>    5  LJ-14            6  Coulomb-14       7  LJ-(SR)          8
>>>>>>> Coulomb-(SR)
>>>>>>>    9  Coul.-recip.    10  COM-Pull-En.    11  Potential       12
>>>>>>> Kinetic-En.
>>>>>>>   13  Total-Energy    14  Conserved-En.   15  Temperature     16  Pressure
>>>>>>>
>>>>>>>   17  Constr.-rmsd    18  Vir-XX          19  Vir-XY          20  Vir-XZ
>>>>>>>
>>>>>>>   21  Vir-YX          22  Vir-YY          23  Vir-YZ          24  Vir-ZX
>>>>>>>
>>>>>>>   25  Vir-ZY          26  Vir-ZZ          27  Pres-XX         28  Pres-XY
>>>>>>>
>>>>>>>   29  Pres-XZ         30  Pres-YX         31  Pres-YY         32  Pres-YZ
>>>>>>>
>>>>>>>   33  Pres-ZX         34  Pres-ZY         35  Pres-ZZ         36
>>>>>>> #Surf*SurfTen
>>>>>>>   37  Mu-X                                38  Mu-Y
>>>>>>>
>>>>>>>   39  Mu-Z                                40  Coul-SR:SOL-SOL
>>>>>>>
>>>>>>>   41  LJ-SR:SOL-SOL                       42  Coul-14:SOL-SOL
>>>>>>>
>>>>>>>   43  LJ-14:SOL-SOL                       44  Coul-SR:SOL-WAL
>>>>>>>
>>>>>>>   45  LJ-SR:SOL-WAL                       46  Coul-14:SOL-WAL
>>>>>>>
>>>>>>>   47  LJ-14:SOL-WAL                       48  Coul-SR:SOL-ZnS
>>>>>>>
>>>>>>>   49  LJ-SR:SOL-ZnS                       50  Coul-14:SOL-ZnS
>>>>>>>
>>>>>>>   51  LJ-14:SOL-ZnS                       52  Coul-SR:SOL-Protein
>>>>>>>
>>>>>>>   53  LJ-SR:SOL-Protein                   54  Coul-14:SOL-Protein
>>>>>>>
>>>>>>>   55  LJ-14:SOL-Protein                   56  Coul-SR:SOL-NA
>>>>>>>
>>>>>>>   57  LJ-SR:SOL-NA    58  Coul-14:SOL-NA  59  LJ-14:SOL-NA    60
>>>>>>> Coul-SR:SOL-CL
>>>>>>>   61  LJ-SR:SOL-CL                        62  Coul-14:SOL-CL
>>>>>>>
>>>>>>>   63  LJ-14:SOL-CL                        64  Coul-SR:SOL-wall0
>>>>>>>
>>>>>>>   65  LJ-SR:SOL-wall0                     66  Coul-14:SOL-wall0
>>>>>>>
>>>>>>>   67  LJ-14:SOL-wall0                     68  Coul-SR:SOL-wall1
>>>>>>>
>>>>>>>   69  LJ-SR:SOL-wall1                     70  Coul-14:SOL-wall1
>>>>>>>
>>>>>>>   71  LJ-14:SOL-wall1                     72  Coul-SR:WAL-WAL
>>>>>>>
>>>>>>>   73  LJ-SR:WAL-WAL                       74  Coul-14:WAL-WAL
>>>>>>>
>>>>>>>   75  LJ-14:WAL-WAL                       76  Coul-SR:WAL-ZnS
>>>>>>>
>>>>>>>   77  LJ-SR:WAL-ZnS                       78  Coul-14:WAL-ZnS
>>>>>>>
>>>>>>>   79  LJ-14:WAL-ZnS                       80  Coul-SR:WAL-Protein
>>>>>>>
>>>>>>>   81  LJ-SR:WAL-Protein                   82  Coul-14:WAL-Protein
>>>>>>>
>>>>>>>   83  LJ-14:WAL-Protein                   84  Coul-SR:WAL-NA
>>>>>>>
>>>>>>>   85  LJ-SR:WAL-NA    86  Coul-14:WAL-NA  87  LJ-14:WAL-NA    88
>>>>>>> Coul-SR:WAL-CL
>>>>>>>   89  LJ-SR:WAL-CL                        90  Coul-14:WAL-CL
>>>>>>>
>>>>>>>   91  LJ-14:WAL-CL                        92  Coul-SR:WAL-wall0
>>>>>>>
>>>>>>>   93  LJ-SR:WAL-wall0                     94  Coul-14:WAL-wall0
>>>>>>>
>>>>>>>   95  LJ-14:WAL-wall0                     96  Coul-SR:WAL-wall1
>>>>>>>
>>>>>>>   97  LJ-SR:WAL-wall1                     98  Coul-14:WAL-wall1
>>>>>>>
>>>>>>>   99  LJ-14:WAL-wall1                    100  Coul-SR:ZnS-ZnS
>>>>>>>
>>>>>>> 101  LJ-SR:ZnS-ZnS                      102  Coul-14:ZnS-ZnS
>>>>>>>
>>>>>>> 103  LJ-14:ZnS-ZnS                      104  Coul-SR:ZnS-Protein
>>>>>>>
>>>>>>> 105  LJ-SR:ZnS-Protein                  106  Coul-14:ZnS-Protein
>>>>>>>
>>>>>>> 107  LJ-14:ZnS-Protein                  108  Coul-SR:ZnS-NA
>>>>>>>
>>>>>>> 109  LJ-SR:ZnS-NA   110  Coul-14:ZnS-NA 111  LJ-14:ZnS-NA   112
>>>>>>> Coul-SR:ZnS-CL
>>>>>>> 113  LJ-SR:ZnS-CL                       114  Coul-14:ZnS-CL
>>>>>>>
>>>>>>> 115  LJ-14:ZnS-CL                       116  Coul-SR:ZnS-wall0
>>>>>>>
>>>>>>> 117  LJ-SR:ZnS-wall0                    118  Coul-14:ZnS-wall0
>>>>>>>
>>>>>>> 119  LJ-14:ZnS-wall0                    120  Coul-SR:ZnS-wall1
>>>>>>>
>>>>>>> 121  LJ-SR:ZnS-wall1                    122  Coul-14:ZnS-wall1
>>>>>>>
>>>>>>> 123  LJ-14:ZnS-wall1                    124  Coul-SR:Protein-Protein
>>>>>>>
>>>>>>> 125  LJ-SR:Protein-Protein              126  Coul-14:Protein-Protein
>>>>>>>
>>>>>>> 127  LJ-14:Protein-Protein              128  Coul-SR:Protein-NA
>>>>>>>
>>>>>>> 129  LJ-SR:Protein-NA                   130  Coul-14:Protein-NA
>>>>>>>
>>>>>>> 131  LJ-14:Protein-NA                   132  Coul-SR:Protein-CL
>>>>>>>
>>>>>>> 133  LJ-SR:Protein-CL                   134  Coul-14:Protein-CL
>>>>>>>
>>>>>>> 135  LJ-14:Protein-CL                   136  Coul-SR:Protein-wall0
>>>>>>>
>>>>>>> 137  LJ-SR:Protein-wall0                138  Coul-14:Protein-wall0
>>>>>>>
>>>>>>> 139  LJ-14:Protein-wall0                140  Coul-SR:Protein-wall1
>>>>>>>
>>>>>>> 141  LJ-SR:Protein-wall1                142  Coul-14:Protein-wall1
>>>>>>>
>>>>>>> 143  LJ-14:Protein-wall1                144  Coul-SR:NA-NA
>>>>>>>
>>>>>>> 145  LJ-SR:NA-NA    146  Coul-14:NA-NA  147  LJ-14:NA-NA    148
>>>>>>> Coul-SR:NA-CL
>>>>>>> 149  LJ-SR:NA-CL                        150  Coul-14:NA-CL
>>>>>>>
>>>>>>> 151  LJ-14:NA-CL                        152  Coul-SR:NA-wall0
>>>>>>>
>>>>>>> 153  LJ-SR:NA-wall0                     154  Coul-14:NA-wall0
>>>>>>>
>>>>>>> 155  LJ-14:NA-wall0                     156  Coul-SR:NA-wall1
>>>>>>>
>>>>>>> 157  LJ-SR:NA-wall1                     158  Coul-14:NA-wall1
>>>>>>>
>>>>>>> 159  LJ-14:NA-wall1 160  Coul-SR:CL-CL  161  LJ-SR:CL-CL    162
>>>>>>> Coul-14:CL-CL
>>>>>>> 163  LJ-14:CL-CL                        164  Coul-SR:CL-wall0
>>>>>>>
>>>>>>> 165  LJ-SR:CL-wall0                     166  Coul-14:CL-wall0
>>>>>>>
>>>>>>> 167  LJ-14:CL-wall0                     168  Coul-SR:CL-wall1
>>>>>>>
>>>>>>> 169  LJ-SR:CL-wall1                     170  Coul-14:CL-wall1
>>>>>>>
>>>>>>> 171  LJ-14:CL-wall1                     172  Coul-SR:wall0-wall0
>>>>>>>
>>>>>>> 173  LJ-SR:wall0-wall0                  174  Coul-14:wall0-wall0
>>>>>>>
>>>>>>> 175  LJ-14:wall0-wall0                  176  Coul-SR:wall0-wall1
>>>>>>>
>>>>>>> 177  LJ-SR:wall0-wall1                  178  Coul-14:wall0-wall1
>>>>>>>
>>>>>>> 179  LJ-14:wall0-wall1                  180  Coul-SR:wall1-wall1
>>>>>>>
>>>>>>> 181  LJ-SR:wall1-wall1                  182  Coul-14:wall1-wall1
>>>>>>>
>>>>>>> 183  LJ-14:wall1-wall1                  184  T-System
>>>>>>>
>>>>>>> 185  Lamb-System
>>>>>>>
>>>>>>> how can i understand that this 4nS simulation is enough for all 30 windows
>>>>>>> which i selected after pulling? as you see i'm doing NVT.i tried to
>>>>>>> calculate temperature(15) and total energy(13) and potential(11) for
>>>>>>> example for first window;
>>>>>>> Energy                      Average   Err.Est.       RMSD  Tot-Drift
>>>>>>> ------------------------------------------------------------
>>>>>>> -------------------
>>>>>>> Potential                    -72708        9.2    227.038   -38.8081
>>>>>>> (kJ/mol)
>>>>>>> Total Energy               -63763.9        8.7    273.747   -34.9771
>>>>>>> (kJ/mol)
>>>>>>> Temperature                 299.977      0.022    5.04346   0.128492  (K)
>>>>>>> plots show that temperature is ok and total energy doesn't have
>>>>>>> considerable fluctuation (except after first moment). but potential
>>>>>> None of those values tell you anything about the convergence of your simulations.
>>>>>>
>>>>>>> fluctuates. since i don't see sharp peaks in PMF (but good trends), is it
>>>>>>> rational to do long time simulation? what is the main clue for knowing
>>>>>>> that? is it potential?
>>>>>> If you want to know if the PMF has converged, calculate it for consecutive, non-overlapping time periods. If they are statistically indistinguishable, you are done. If they are still changing over time, you need longer runs.
>>>>> You mean i should use the output Of 4nS simulation, as an input for,for example next 10nS and at the end i have simulated it for 14nS,yes?
>>>> I don't have any idea about what arbitrary amount of time you should target for your simulation, but you need to let convergence testing be your guide.
>>>>
>>>>> What do you mean "statistically", would you please give me an example?
>>>> Use the bootstrapping method of gmx wham to produce error estimates. Then plot the PMF curves and if they are overlapping within error, then you have an argument for convergence.
>>>>
>>>> -Justin
>>>>
>>>> -- 
>>>> ==================================================
>>>>
>>>> Justin A. Lemkul, Ph.D.
>>>> Assistant Professor
>>>> Virginia Tech Department of Biochemistry
>>>>
>>>> 303 Engel Hall
>>>> 340 West Campus Dr.
>>>> Blacksburg, VA 24061
>>>>
>>>> jalemkul at vt.edu | (540) 231-3129
>>>> http://www.biochem.vt.edu/people/faculty/JustinLemkul.html
>>>>
>>>> ==================================================
>>>>
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>> -- 
>> ==================================================
>>
>> Justin A. Lemkul, Ph.D.
>> Assistant Professor
>> Virginia Tech Department of Biochemistry
>>
>> 303 Engel Hall
>> 340 West Campus Dr.
>> Blacksburg, VA 24061
>>
>> jalemkul at vt.edu | (540) 231-3129
>> http://www.biochem.vt.edu/people/faculty/JustinLemkul.html
>>
>> ==================================================
>>
>> -- 
>> Gromacs Users mailing list
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-- 
==================================================

Justin A. Lemkul, Ph.D.
Assistant Professor
Virginia Tech Department of Biochemistry

303 Engel Hall
340 West Campus Dr.
Blacksburg, VA 24061

jalemkul at vt.edu | (540) 231-3129
http://www.biochem.vt.edu/people/faculty/JustinLemkul.html

==================================================



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