[gmx-users] Schlitter Configurational entropy 'NaN'

David van der Spoel spoel at xray.bmc.uu.se
Fri May 16 07:53:04 CEST 2014


On 2014-05-16 06:03, tarak karmakar wrote:
>>
>> What does g_covar print?
>>
>> It seems the problem might be there, because the jump by 10 orders of
>> magnitude in eigenvalue does not seem reasonable.
>>
>
> g_covar prints the following
>
> Analysis is non-mass weighted
> Fit is non-mass weighted
> Diagonalized the 1386x1386 covariance matrix
> Trace of the covariance matrix before diagonalizing: 8.72034
> Trace of the covariance matrix after diagonalizing: 8.72034
>
> Wrote 1386 eigenvalues to eigenval.xvg
> Wrote reference structure to eigenvec.trr
> Wrote average structure to average.pdb and eigenvec.trr
> Wrote eigenvectors 1 to 1000 to eigenvec.trr
>
> Another more subtle issue might be the number of frames used for the
> analysis. Did you happen to have 1000 frames only? In that case the
> remaining degrees of freedom might be ill-defined.
>
> Yes. I do have 1000 frames only.
> In the previous case I had skipped some steps (trjconv with pbc -nojump
> -skip 10) to get a shorter trajectory. But when I took the full trajectory
> 10000 the eigenvalues are coming out good.
>
>         996 9.46356e-05
>         997 9.38922e-05
>         998 9.38014e-05
>         999 9.36644e-05
>        1000 9.33975e-05
>        1001 9.33863e-05
>        1002 9.296e-05
>        1003 9.28913e-05
>        1004 9.26346e-05
>        1005 9.25611e-05
>
> The Entropy due to the Quasi Harmonic approximation is 6239.63 J/mol K
> The Entropy due to the Schlitter formula is 6950.97 J/mol K
>
> Tarak
>
>

OK, thanks for your help in debugging this. I have now uploaded a fix to 
gromacs 4.6. https://gerrit.gromacs.org/#/c/3447/


>
>
>
>
>
> On Thu, May 15, 2014 at 11:05 PM, David van der Spoel
> <spoel at xray.bmc.uu.se>wrote:
>
>> On 2014-05-15 19:20, David van der Spoel wrote:
>>
>>> On 2014-05-15 18:41, tarak karmakar wrote:
>>>
>>>> Hi Justin,
>>>> That's true and it is a C code and 0 index loop.
>>>> Then the strange jump 999 to 1000 came in to the picture.
>>>> But what about dealing with very small numbers?
>>>>
>>> What does g_covar print?
>>>
>>> It seems the problem might be there, because the jump by 10 orders of
>>> magnitude in eigenvalue does not seem reasonable.
>>>
>>
>> Another more subtle issue might be the number of frames used for the
>> analysis. Did you happen to have 1000 frames only? In that case the
>> remaining degrees of freedom might be ill-defined.
>>
>>
>>>
>>>>
>>>> Tarak
>>>>
>>>>
>>>> On Thu, May 15, 2014 at 9:30 PM, Justin Lemkul <jalemkul at vt.edu> wrote:
>>>>
>>>>
>>>>>
>>>>> On 5/15/14, 11:51 AM, tarak karmakar wrote:
>>>>>
>>>>>   Part of the eigenval.xvg file
>>>>>>
>>>>>>           995 3.02979e-06
>>>>>>           996 2.98051e-06
>>>>>>           997 2.93131e-06
>>>>>>           998 2.75594e-06
>>>>>>           999 2.69955e-06
>>>>>>          1000 2.56434e-06
>>>>>>          1001 2.66401e-16
>>>>>>          1002 1.43252e-16
>>>>>>          1003 1.0735e-16
>>>>>>          1004 8.0728e-17
>>>>>>          1005 4.3465e-17
>>>>>>          1006 1.60571e-17
>>>>>>          1007 1.49006e-17
>>>>>>          1008 1.44694e-17
>>>>>>          1009 1.07083e-17
>>>>>>          1010 9.77564e-18
>>>>>>          1011 8.25739e-18
>>>>>>          1012 8.18473e-18
>>>>>>          1013 6.85267e-18
>>>>>>          1014 6.79135e-18
>>>>>>          1015 5.7498e-18
>>>>>>          1016 5.49917e-18
>>>>>>          1017 4.84525e-18
>>>>>>          1018 4.15989e-18
>>>>>>          1019 4.06407e-18
>>>>>>          1020 3.70677e-18
>>>>>>          .............................
>>>>>>          .............................
>>>>>>          1362 -3.16429e-18
>>>>>>          1363 -3.40673e-18
>>>>>>          1364 -3.85766e-18
>>>>>>          1365 -4.16796e-18
>>>>>>          1366 -4.16839e-18
>>>>>>          1367 -4.17689e-18
>>>>>>          1368 -4.48977e-18
>>>>>>          1369 -4.54731e-18
>>>>>>          1370 -4.58794e-18
>>>>>>          1371 -4.86076e-18
>>>>>>          1372 -5.05864e-18
>>>>>>          1373 -5.73908e-18
>>>>>>          1374 -6.1385e-18
>>>>>>          1375 -6.98907e-18
>>>>>>          1376 -7.5897e-18
>>>>>>          1377 -1.23406e-17
>>>>>>          1378 -1.24701e-17
>>>>>>          1379 -1.41182e-17
>>>>>>          1380 -1.47709e-17
>>>>>>          1381 -1.50144e-17
>>>>>>          1382 -5.73596e-17
>>>>>>          1383 -1.03466e-16
>>>>>>          1384 -1.277e-16
>>>>>>          1385 -1.64873e-16
>>>>>>          1386 -3.2657e-16
>>>>>>
>>>>>> These eigenvalues are very less compared to the below 1000 numbers.
>>>>>> I see there is no strange jump from 999 to 1000 but from 1000 to 1001.
>>>>>>
>>>>>>
>>>>>>   The array in the code is zero-indexed, so this is actually the
>>>>> location of
>>>>> the problem.
>>>>>
>>>>> -Justin
>>>>>
>>>>>
>>>>>    Lambda values are considered to be zero in these cases and thus
>>>>>
>>>>>> w      = sqrt(BOLTZMANN*temp/lambda)/NANO = infinity
>>>>>> &
>>>>>> dd = 1+kteh*eigval[i];
>>>>>>         deter += log(dd)
>>>>>> is failed.
>>>>>>
>>>>>> i =  1000 w =        inf lam =          0 hwkT =        inf dS =
>>>>>> -nan
>>>>>> i =  1001 w =        inf lam =          0 hwkT =        inf dS =
>>>>>> -nan
>>>>>> i =  1002 w =        inf lam =          0 hwkT =        inf dS =
>>>>>> -nan
>>>>>>
>>>>>> So, there is precision problem in the code; 10^-16 is taken as zero!!
>>>>>>
>>>>>> Tarak
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>> On Thu, May 15, 2014 at 5:23 PM, David van der Spoel
>>>>>> <spoel at xray.bmc.uu.se>wrote:
>>>>>>
>>>>>>    On 2014-05-15 11:40, tarak karmakar wrote:
>>>>>>
>>>>>>>
>>>>>>>    Dear Sir,
>>>>>>>
>>>>>>>>
>>>>>>>> Thank you again for guiding me towards this. Got some clue.
>>>>>>>> The g_anaeig code is
>>>>>>>> ............................................................
>>>>>>>> ............................................................
>>>>>>>> .................
>>>>>>>> static void calc_entropy_qh(FILE *fp,int n,real eigval[],real
>>>>>>>> temp,int
>>>>>>>> nskip)
>>>>>>>> {
>>>>>>>>       int    i;
>>>>>>>>       double hwkT,w,dS,S=0;
>>>>>>>>       double hbar,lambda;
>>>>>>>>
>>>>>>>>       hbar = PLANCK1/(2*M_PI);
>>>>>>>>       for(i=0; (i<n-nskip); i++) {
>>>>>>>>         if (eigval[i] > 0) {
>>>>>>>>           lambda = eigval[i]*AMU;
>>>>>>>>           w      = sqrt(BOLTZMANN*temp/lambda)/NANO;
>>>>>>>>           hwkT   = (hbar*w)/(BOLTZMANN*temp);
>>>>>>>>           dS     = (hwkT/(exp(hwkT) - 1) - log(1-exp(-hwkT)));
>>>>>>>>           S     += dS;
>>>>>>>>           if (debug)
>>>>>>>>         fprintf(debug,"i = %5d w = %10g lam = %10g hwkT = %10g dS =
>>>>>>>> %10g\n",
>>>>>>>>             i,w,lambda,hwkT,dS);
>>>>>>>>         }
>>>>>>>>         else {
>>>>>>>>           fprintf(stderr,"eigval[%d] = %g\n",i,eigval[i]);
>>>>>>>>           w = 0;
>>>>>>>>         }
>>>>>>>>       }
>>>>>>>>       fprintf(fp,"The Entropy due to the Quasi Harmonic
>>>>>>>> approximation is
>>>>>>>> %g
>>>>>>>> J/mol K\n",
>>>>>>>>           S*RGAS);
>>>>>>>> }
>>>>>>>>
>>>>>>>> static void calc_entropy_schlitter(FILE *fp,int n,int nskip,
>>>>>>>>                        real *eigval,real temp)
>>>>>>>> {
>>>>>>>>       double dd,deter;
>>>>>>>>       int    *indx;
>>>>>>>>       int    i,j,k,m;
>>>>>>>>       char   buf[256];
>>>>>>>>       double hbar,kt,kteh,S;
>>>>>>>>
>>>>>>>>       hbar = PLANCK1/(2*M_PI);
>>>>>>>>       kt   = BOLTZMANN*temp;
>>>>>>>>       kteh = kt*exp(2.0)/(hbar*hbar)*AMU*(NANO*NANO);
>>>>>>>>       if (debug)
>>>>>>>>         fprintf(debug,"n = %d, nskip = %d kteh = %g\n",n,nskip,kteh);
>>>>>>>>
>>>>>>>>       deter = 0;
>>>>>>>>       for(i=0; (i<n-nskip); i++) {
>>>>>>>>         dd = 1+kteh*eigval[i];
>>>>>>>>         deter += log(dd);
>>>>>>>>       }
>>>>>>>>       S = 0.5*RGAS*deter;
>>>>>>>>
>>>>>>>>       fprintf(fp,"The Entropy due to the Schlitter formula is %g J/mol
>>>>>>>> K\n",S);
>>>>>>>> }
>>>>>>>> ............................................................
>>>>>>>> ..............................................................
>>>>>>>> What I got from the 'g_anaeig_d.debug' file is given below
>>>>>>>>
>>>>>>>> i =     0 w = 1.06303e+12 lam = 3.66537e-27 hwkT =  0.0270659 dS =
>>>>>>>> 4.60951
>>>>>>>> i =     1 w = 1.50699e+12 lam = 1.82384e-27 hwkT =  0.0383696 dS =
>>>>>>>> 4.26055
>>>>>>>> i =     2 w = 1.62965e+12 lam = 1.55961e-27 hwkT =  0.0414928 dS =
>>>>>>>> 4.18231
>>>>>>>> i =     3 w = 2.02202e+12 lam = 1.01306e-27 hwkT =  0.0514829 dS =
>>>>>>>> 3.96662
>>>>>>>> i =     4 w = 2.80273e+12 lam = 5.27285e-28 hwkT =  0.0713605 dS =
>>>>>>>> 3.64022
>>>>>>>> i =     5 w = 3.1712e+12 lam = 4.11871e-28 hwkT =  0.0807422 dS =
>>>>>>>>     3.51677
>>>>>>>> i =     6 w = 3.45782e+12 lam = 3.46419e-28 hwkT =  0.0880401 dS =
>>>>>>>> 3.43029
>>>>>>>> i =     7 w = 3.56568e+12 lam = 3.25778e-28 hwkT =  0.0907862 dS =
>>>>>>>> 3.39959
>>>>>>>> i =     8 w = 4.00962e+12 lam = 2.57633e-28 hwkT =   0.102089 dS =
>>>>>>>> 3.28234
>>>>>>>> i =     9 w = 4.4611e+12 lam = 2.08125e-28 hwkT =   0.113584 dS =
>>>>>>>>     3.17575
>>>>>>>> i =    10 w = 4.6037e+12 lam = 1.95431e-28 hwkT =   0.117215 dS =
>>>>>>>>     3.14431
>>>>>>>> i =    11 w = 5.01062e+12 lam = 1.64977e-28 hwkT =   0.127576 dS =
>>>>>>>> 3.05972
>>>>>>>> i =    12 w = 5.31327e+12 lam = 1.46718e-28 hwkT =   0.135282 dS =
>>>>>>>> 3.00116
>>>>>>>> i =    13 w = 5.51169e+12 lam = 1.36345e-28 hwkT =   0.140334 dS =
>>>>>>>> 2.96455
>>>>>>>> i =    14 w = 5.70613e+12 lam = 1.27211e-28 hwkT =   0.145284 dS =
>>>>>>>> 2.92994
>>>>>>>> i =    15 w = 5.8637e+12 lam = 1.20466e-28 hwkT =   0.149296 dS =
>>>>>>>>     2.90275
>>>>>>>> i =    16 w = 6.01592e+12 lam = 1.14447e-28 hwkT =   0.153172 dS =
>>>>>>>> 2.87717
>>>>>>>> ----------------------
>>>>>>>> .......................
>>>>>>>> i =   996 w = 9.2246e+14 lam = 4.86757e-33 hwkT =    23.4869 dS =
>>>>>>>> 1.54425e-09
>>>>>>>> i =   997 w = 9.51359e+14 lam = 4.57635e-33 hwkT =    24.2226 dS =
>>>>>>>> 7.62131e-10
>>>>>>>> i =   998 w = 9.61243e+14 lam = 4.48271e-33 hwkT =    24.4743 dS =
>>>>>>>> 5.98465e-10
>>>>>>>> i =   999 w = 9.86259e+14 lam = 4.25819e-33 hwkT =    25.1113 dS =
>>>>>>>> 3.2445e-10
>>>>>>>> i =  1000 w =        inf lam =          0 hwkT =        inf dS =
>>>>>>>> -nan
>>>>>>>> i =  1001 w =        inf lam =          0 hwkT =        inf dS =
>>>>>>>> -nan
>>>>>>>> i =  1002 w =        inf lam =          0 hwkT =        inf dS =
>>>>>>>> -nan
>>>>>>>> ......................
>>>>>>>> ..................
>>>>>>>> i =  1370 w =        inf lam =          0 hwkT =        inf dS =
>>>>>>>> -nan
>>>>>>>> i =  1371 w =        inf lam =          0 hwkT =        inf dS =
>>>>>>>> -nan
>>>>>>>> i =  1372 w =        inf lam =          0 hwkT =        inf dS =
>>>>>>>> -nan
>>>>>>>> i =  1373 w =        inf lam =          0 hwkT =        inf dS =
>>>>>>>> -nan
>>>>>>>> i =  1374 w =        inf lam =          0 hwkT =        inf dS =
>>>>>>>> -nan
>>>>>>>> i =  1375 w =        inf lam =          0 hwkT =        inf dS =
>>>>>>>> -nan
>>>>>>>> i =  1376 w =        inf lam =          0 hwkT =        inf dS =
>>>>>>>> -nan
>>>>>>>> i =  1377 w =        inf lam =          0 hwkT =        inf dS =
>>>>>>>> -nan
>>>>>>>> i =  1378 w =        inf lam =          0 hwkT =        inf dS =
>>>>>>>> -nan
>>>>>>>> i =  1379 w =        inf lam =          0 hwkT =        inf dS =
>>>>>>>> -nan
>>>>>>>> n = 1386, nskip = 6 kteh = 4569.58
>>>>>>>> Opening library file /usr/share/gromacs/top/gurgle.dat
>>>>>>>>
>>>>>>>>
>>>>>>>> It is very interesting that the code printed 'nan' after 999 th term.
>>>>>>>> What
>>>>>>>> does this mean?
>>>>>>>> Is there any upper limit of number of atoms (c-alpha here)?
>>>>>>>>
>>>>>>>>    Check your eigval.xvg file, what is the value at i = 1000?
>>>>>>>>
>>>>>>> It seems that lambda is the problem, hence I suspect the
>>>>>>> eigval[1000] to
>>>>>>> be strange.
>>>>>>>
>>>>>>>
>>>>>>>    Tarak
>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>> On Thu, May 15, 2014 at 2:54 PM, David van der Spoel
>>>>>>>> <spoel at xray.bmc.uu.se>wrote:
>>>>>>>>
>>>>>>>>     On 2014-05-15 10:51, tarak karmakar wrote:
>>>>>>>>
>>>>>>>>
>>>>>>>>>        | Is your system far out of equilibrium?
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>> It should not be as I have simulated the system for 100ns. Few
>>>>>>>>>> properties
>>>>>>>>>> to check to get the feelings of equilibrium are looking good.
>>>>>>>>>>
>>>>>>>>>> |Do the eigenvalues look reasonable?
>>>>>>>>>> Yes. File is attached.
>>>>>>>>>>
>>>>>>>>>> | Or is your system very large?
>>>>>>>>>> My system is a protein dimer.
>>>>>>>>>>
>>>>>>>>>> It creates the following covariance matrix (c-alpha atoms)
>>>>>>>>>>
>>>>>>>>>> Constructing covariance matrix (1386x1386)
>>>>>>>>>>
>>>>>>>>>>     That is big.
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>> Try running g_anaeig -debug 1 and check the output file
>>>>>>>>> g_anaeig.debug.
>>>>>>>>> Then check the source code (gmx_anaeig.c) to see whether the
>>>>>>>>> evaluation
>>>>>>>>> of
>>>>>>>>> the entropy can be made more numerically stable.
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>     eigenvec.trr file is also attached.
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>> Mail with the attached files
>>>>>>>>>> "Needs moderator approval because of the file size."
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> Thanks,
>>>>>>>>>> Tarak
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> On Thu, May 15, 2014 at 2:19 PM, tarak karmakar
>>>>>>>>>> <tarak20489 at gmail.com
>>>>>>>>>>
>>>>>>>>>>    wrote:
>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>>       | Is your system far out of equilibrium?
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>   It should not be as I have simulated the system for 100ns. Few
>>>>>>>>>>> properties
>>>>>>>>>>> to check to get the feelings of equilibrium are looking good.
>>>>>>>>>>>
>>>>>>>>>>> |Do the eigenvalues look reasonable?
>>>>>>>>>>> Yes. File is attached.
>>>>>>>>>>>
>>>>>>>>>>> | Or is your system very large?
>>>>>>>>>>> My system is a protein dimer.
>>>>>>>>>>>
>>>>>>>>>>> It creates the following covariance matrix (c-alpha atoms)
>>>>>>>>>>>
>>>>>>>>>>> Constructing covariance matrix (1386x1386)
>>>>>>>>>>>
>>>>>>>>>>> eigenvec.trr file is also attached.
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> Thanks,
>>>>>>>>>>> Tarak
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> On Thu, May 15, 2014 at 2:06 PM, David van der Spoel <
>>>>>>>>>>> spoel at xray.bmc.uu.se
>>>>>>>>>>>
>>>>>>>>>>>     wrote:
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>>       On 2014-05-15 10:30, tarak karmakar wrote:
>>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>>       Dear Sir,
>>>>>>>>>>>>
>>>>>>>>>>>>    Thanks for the quick reply.
>>>>>>>>>>>>
>>>>>>>>>>>>> Using g_anaeig_d I've got both of them as 'nan'
>>>>>>>>>>>>>
>>>>>>>>>>>>> The Entropy due to the Quasi Harmonic approximation is -nan
>>>>>>>>>>>>> J/mol K
>>>>>>>>>>>>> The Entropy due to the Schlitter formula is nan J/mol K
>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>>>     Interesting. Is your system far out of equilibrium? Do the
>>>>>>>>>>>>>
>>>>>>>>>>>>>   eigenvalues
>>>>>>>>>>>> look reasonable? Or is your system very large?
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>>      Tarak
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>>> On Thu, May 15, 2014 at 1:30 PM, David van der Spoel
>>>>>>>>>>>>> <spoel at xray.bmc.uu.se>wrote:
>>>>>>>>>>>>>
>>>>>>>>>>>>>       On 2014-05-15 09:07, tarak karmakar wrote:
>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>>>        Dear All,
>>>>>>>>>>>>>
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>     I wanted to calculate configurational entropy of a
>>>>>>>>>>>>>> protein by
>>>>>>>>>>>>>> using
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>   g_covar
>>>>>>>>>>>>>>> and g_anaeig as follows,
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> g_covar -f ../traj.xtc -s ../npt_prod -o eigenval -v
>>>>>>>>>>>>>>> eigenvec.trr
>>>>>>>>>>>>>>> -av
>>>>>>>>>>>>>>> average.pdb
>>>>>>>>>>>>>>> g_anaeig -v eigenvec.trr -entropy -temp 300
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> I got the following results
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> The Entropy due to the Quasi Harmonic approximation is 31440.3
>>>>>>>>>>>>>>> J/mol
>>>>>>>>>>>>>>> K
>>>>>>>>>>>>>>> The Entropy due to the Schlitter formula is nan J/mol K
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> I went back to check the eigenvector file by dumping it to
>>>>>>>>>>>>>>> a new
>>>>>>>>>>>>>>> file
>>>>>>>>>>>>>>> 'dump'. There is no 'nan' indeed.
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> Could anyone comment on why I'm getting Schlitter entropy as
>>>>>>>>>>>>>>> 'nan'?
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> Thanks and regards,
>>>>>>>>>>>>>>> Tarak
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>        Numerical error due to large numbers. Try compiling
>>>>>>>>>>>>>>> gromacs
>>>>>>>>>>>>>>> in
>>>>>>>>>>>>>>> double
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>      precision.
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>   --
>>>>>>>>>>>>>> David van der Spoel, Ph.D., Professor of Biology
>>>>>>>>>>>>>> Dept. of Cell & Molec. Biol., Uppsala University.
>>>>>>>>>>>>>> Box 596, 75124 Uppsala, Sweden. Phone:  +46184714205.
>>>>>>>>>>>>>> spoel at xray.bmc.uu.se    http://folding.bmc.uu.se
>>>>>>>>>>>>>> --
>>>>>>>>>>>>>> Gromacs Users mailing list
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> * Please search the archive at http://www.gromacs.org/
>>>>>>>>>>>>>> Support/Mailing_Lists/GMX-Users_List before posting!
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> * Can't post? Read http://www.gromacs.org/
>>>>>>>>>>>>>> Support/Mailing_Lists
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> * For (un)subscribe requests visit
>>>>>>>>>>>>>> https://maillist.sys.kth.se/mailman/listinfo/gromacs.org_
>>>>>>>>>>>>>> gmx-usersor
>>>>>>>>>>>>>> send a mail to gmx-users-request at gromacs.org.
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>     --
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>   David van der Spoel, Ph.D., Professor of Biology
>>>>>>>>>>>>>
>>>>>>>>>>>> Dept. of Cell & Molec. Biol., Uppsala University.
>>>>>>>>>>>> Box 596, 75124 Uppsala, Sweden. Phone:  +46184714205.
>>>>>>>>>>>> spoel at xray.bmc.uu.se    http://folding.bmc.uu.se
>>>>>>>>>>>> --
>>>>>>>>>>>> Gromacs Users mailing list
>>>>>>>>>>>>
>>>>>>>>>>>> * Please search the archive at http://www.gromacs.org/
>>>>>>>>>>>> Support/Mailing_Lists/GMX-Users_List before posting!
>>>>>>>>>>>>
>>>>>>>>>>>> * Can't post? Read http://www.gromacs.org/Support/Mailing_Lists
>>>>>>>>>>>>
>>>>>>>>>>>> * For (un)subscribe requests visit
>>>>>>>>>>>> https://maillist.sys.kth.se/mailman/listinfo/gromacs.org_
>>>>>>>>>>>> gmx-usersor
>>>>>>>>>>>>
>>>>>>>>>>>> send a mail to gmx-users-request at gromacs.org.
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>    --
>>>>>>>>>>
>>>>>>>>> David van der Spoel, Ph.D., Professor of Biology
>>>>>>>>> Dept. of Cell & Molec. Biol., Uppsala University.
>>>>>>>>> Box 596, 75124 Uppsala, Sweden. Phone:  +46184714205.
>>>>>>>>> spoel at xray.bmc.uu.se    http://folding.bmc.uu.se
>>>>>>>>> --
>>>>>>>>> Gromacs Users mailing list
>>>>>>>>>
>>>>>>>>> * Please search the archive at http://www.gromacs.org/
>>>>>>>>> Support/Mailing_Lists/GMX-Users_List before posting!
>>>>>>>>>
>>>>>>>>> * Can't post? Read http://www.gromacs.org/Support/Mailing_Lists
>>>>>>>>>
>>>>>>>>> * For (un)subscribe requests visit
>>>>>>>>> https://maillist.sys.kth.se/mailman/listinfo/gromacs.org_gmx-usersor
>>>>>>>>>
>>>>>>>>> send a mail to gmx-users-request at gromacs.org.
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>   --
>>>>>>> David van der Spoel, Ph.D., Professor of Biology
>>>>>>> Dept. of Cell & Molec. Biol., Uppsala University.
>>>>>>> Box 596, 75124 Uppsala, Sweden. Phone:  +46184714205.
>>>>>>> spoel at xray.bmc.uu.se    http://folding.bmc.uu.se
>>>>>>> --
>>>>>>> Gromacs Users mailing list
>>>>>>>
>>>>>>> * Please search the archive at http://www.gromacs.org/
>>>>>>> Support/Mailing_Lists/GMX-Users_List before posting!
>>>>>>>
>>>>>>> * Can't post? Read http://www.gromacs.org/Support/Mailing_Lists
>>>>>>>
>>>>>>> * For (un)subscribe requests visit
>>>>>>> https://maillist.sys.kth.se/mailman/listinfo/gromacs.org_gmx-users or
>>>>>>> send a mail to gmx-users-request at gromacs.org.
>>>>>>>
>>>>>>>
>>>>>>>   --
>>>>> ==================================================
>>>>>
>>>>> Justin A. Lemkul, Ph.D.
>>>>> Ruth L. Kirschstein NRSA Postdoctoral Fellow
>>>>>
>>>>> Department of Pharmaceutical Sciences
>>>>> School of Pharmacy
>>>>> Health Sciences Facility II, Room 601
>>>>> University of Maryland, Baltimore
>>>>> 20 Penn St.
>>>>> Baltimore, MD 21201
>>>>>
>>>>> jalemkul at outerbanks.umaryland.edu | (410) 706-7441
>>>>> http://mackerell.umaryland.edu/~jalemkul
>>>>>
>>>>> ==================================================
>>>>>
>>>>> --
>>>>> Gromacs Users mailing list
>>>>>
>>>>> * Please search the archive at http://www.gromacs.org/
>>>>> Support/Mailing_Lists/GMX-Users_List before posting!
>>>>>
>>>>> * Can't post? Read http://www.gromacs.org/Support/Mailing_Lists
>>>>>
>>>>> * For (un)subscribe requests visit
>>>>> https://maillist.sys.kth.se/mailman/listinfo/gromacs.org_gmx-users or
>>>>> send a mail to gmx-users-request at gromacs.org.
>>>>>
>>>>>
>>>
>>>
>>
>> --
>> David van der Spoel, Ph.D., Professor of Biology
>> Dept. of Cell & Molec. Biol., Uppsala University.
>> Box 596, 75124 Uppsala, Sweden. Phone:  +46184714205.
>> spoel at xray.bmc.uu.se    http://folding.bmc.uu.se
>> --
>> Gromacs Users mailing list
>>
>> * Please search the archive at http://www.gromacs.org/
>> Support/Mailing_Lists/GMX-Users_List before posting!
>>
>> * Can't post? Read http://www.gromacs.org/Support/Mailing_Lists
>>
>> * For (un)subscribe requests visit
>> https://maillist.sys.kth.se/mailman/listinfo/gromacs.org_gmx-users or
>> send a mail to gmx-users-request at gromacs.org.
>>


-- 
David van der Spoel, Ph.D., Professor of Biology
Dept. of Cell & Molec. Biol., Uppsala University.
Box 596, 75124 Uppsala, Sweden. Phone:	+46184714205.
spoel at xray.bmc.uu.se    http://folding.bmc.uu.se


More information about the gromacs.org_gmx-users mailing list