Re: [gmx-users] System reaches ~124K after simulated annealing upto 300K (Justin Lemkul)
On 6/17/17 2:23 AM, Apramita Chand wrote: Dear Justin, The normal (non-annealing) equilibration works fine. 100ps of NVT and it easily reaches 300K. There are no error messages. Am I doing the simulated annealing correctly? Looks fine, other than generating velocities at 300 K but specifying 0 K as the initial temperature for annealing. If you're just equilibrating a system, I think annealing is a waste of time. -Justin yours sincerely Apramita Message: 4 Date: Fri, 16 Jun 2017 13:21:18 -0400 From: Justin LemkulTo: gmx-us...@gromacs.org Subject: Re: [gmx-users] System reaches ~124K after simulated annealing upto 300K Message-ID: <8fe97070-c577-de07-ba25-64a7230f6...@vt.edu> Content-Type: text/plain; charset=utf-8; format=flowed On 6/16/17 10:38 AM, Apramita Chand wrote: Dear All, I have used the following nvt.mdp file to gradually warm my system upto 300K but just reach upto 124K. I have used variety of options in the simulated annealing like taking less no. of time intervals but in vain Then, I have to perform manually the gradual heating process which takes me to 300K Why doesn't this work? Anything that goes that haywire is simply unstable. De-complicate your life and try to do a normal (non-annealing) MD and see if it works. If not, then diagnose further. http://www.gromacs.org/Documentation/Terminology/Blowing_Up#Diagnosing_an_ Unstable_System -Justin Yours sincerely, Apramita VARIOUS PREPROCESSING OPTIONS define = -DPOSRES ; RUN CONTROL PARAMETERS integrator = md dt = 0.002 ; time step (in ps) nsteps = 5 ; number of steps ; OUTPUT CONTROL OPTIONS nstxout = 500 ; save coordinates every ps nstvout = 500 ; save velocities every ps nstenergy = 500 ; save energies every ps nstlog = 500 ; update log file every ps energygrps = Protein SOL ; NEIGHBORSEARCHING PARAMETERS nstlist = 5 ns_type = grid pbc = xyz rlist= 0.9 ; OPTIONS FOR ELECTROSTATICS AND VDW coulombtype = PME ; Particle Mesh Ewald for long-range electrostatics pme_order= 4; cubic interpolation fourierspacing = 0.16 ; grid spacing for FFT rcoulomb = 0.9 vdw-type = Cut-off rvdw = 1.4 ; Temperature coupling 5 tcoupl = v-rescale; Couple temperature to external heat bath according to velocity re-scale method tc-grps = Protein SOL ; Use separate heat baths for Protein and Non-Protein groups tau_t= 0.10.1; Coupling time constant, controlling strength of coupling ref_t= 300300; Temperature of heat bath ; Dispersion correction DispCorr = EnerPres ; account for vdw cut-off ; Pressure coupling is off pcoupl = no; no pressure coupling in NVT ; GENERATE VELOCITIES FOR STARTUP RUN gen_vel = yes; Assign velocities to particles by taking them randomly from a Maxwell distribution Different numbers give different sets of velocities gen_temp = 300; Temperature to generate corresponding Maxwell distribution gen_seed = -1 ; Seed for (semi) random number generation. ; OPTIONS FOR BONDS constraints = all-bonds ; All bonds will be treated as constraints (fixed length) continuation = no ; first dynamics run constraint_algorithm = lincs; holonomic constraints lincs_iter = 1; accuracy of LINCS lincs_order = 4; also related to accuracy ; Simulated Annealing annealing= single single annealing_npoints= 4 4 annealing_time= 0 50 75 100 0 50 75 100 annealing_temp= 0 100 200 300 0 100 200 300 -- == Justin A. Lemkul, Ph.D. Ruth L. Kirschstein NRSA Postdoctoral Fellow Department of Pharmaceutical Sciences School of Pharmacy Health Sciences Facility II, Room 629 University of Maryland, Baltimore 20 Penn St. Baltimore, MD 21201 jalem...@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-requ...@gromacs.org. End of gromacs.org_gmx-users Digest, Vol 158, Issue 106 *** -- ==
Re: [gmx-users] System reaches ~124K after simulated annealing upto 300K (Justin Lemkul)
Dear Justin, The normal (non-annealing) equilibration works fine. 100ps of NVT and it easily reaches 300K. There are no error messages. Am I doing the simulated annealing correctly? yours sincerely Apramita Message: 4 Date: Fri, 16 Jun 2017 13:21:18 -0400 From: Justin LemkulTo: gmx-us...@gromacs.org Subject: Re: [gmx-users] System reaches ~124K after simulated annealing upto 300K Message-ID: <8fe97070-c577-de07-ba25-64a7230f6...@vt.edu> Content-Type: text/plain; charset=utf-8; format=flowed On 6/16/17 10:38 AM, Apramita Chand wrote: > Dear All, > I have used the following nvt.mdp file to gradually warm my system upto > 300K but just reach upto 124K. I have used variety of options in the > simulated annealing like taking less no. of time intervals but in vain > Then, I have to perform manually the gradual heating process which takes me > to 300K > Why doesn't this work? > Anything that goes that haywire is simply unstable. De-complicate your life and try to do a normal (non-annealing) MD and see if it works. If not, then diagnose further. http://www.gromacs.org/Documentation/Terminology/Blowing_Up#Diagnosing_an_ Unstable_System -Justin > Yours sincerely, > Apramita > > > > VARIOUS PREPROCESSING OPTIONS > define = -DPOSRES > ; RUN CONTROL PARAMETERS > integrator = md > dt = 0.002 ; time step (in ps) > nsteps = 5 ; number of steps > ; OUTPUT CONTROL OPTIONS > nstxout = 500 ; save coordinates every ps > nstvout = 500 ; save velocities every ps > nstenergy = 500 ; save energies every ps > nstlog = 500 ; update log file every ps > energygrps = Protein SOL > ; NEIGHBORSEARCHING PARAMETERS > nstlist = 5 > ns_type = grid > pbc = xyz > rlist= 0.9 > ; OPTIONS FOR ELECTROSTATICS AND VDW > coulombtype = PME ; Particle Mesh Ewald for long-range > electrostatics > pme_order= 4; cubic interpolation > fourierspacing = 0.16 ; grid spacing for FFT > rcoulomb = 0.9 > vdw-type = Cut-off > rvdw = 1.4 > ; Temperature coupling > 5 > tcoupl = v-rescale; Couple temperature to > external heat bath according to velocity re-scale method > tc-grps = Protein SOL ; Use separate heat baths for > Protein and Non-Protein groups > tau_t= 0.10.1; Coupling time constant, > controlling strength of coupling > ref_t= 300300; Temperature of heat bath > ; Dispersion correction > DispCorr = EnerPres ; account for vdw cut-off > ; Pressure coupling is off > pcoupl = no; no pressure coupling in > NVT > ; GENERATE VELOCITIES FOR STARTUP RUN > gen_vel = yes; Assign velocities to particles by > taking > them randomly from a Maxwell distribution > Different numbers give different sets of velocities > gen_temp = 300; Temperature to generate corresponding > Maxwell distribution > gen_seed = -1 ; Seed for (semi) random number > generation. > ; OPTIONS FOR BONDS > constraints = all-bonds ; All bonds will be treated as > constraints (fixed length) > continuation = no ; first dynamics run > constraint_algorithm = lincs; holonomic constraints > lincs_iter = 1; accuracy of LINCS > lincs_order = 4; also related to accuracy > ; Simulated Annealing > annealing= single single > annealing_npoints= 4 4 > annealing_time= 0 50 75 100 0 50 75 100 > annealing_temp= 0 100 200 300 0 100 200 300 > -- == Justin A. Lemkul, Ph.D. Ruth L. Kirschstein NRSA Postdoctoral Fellow Department of Pharmaceutical Sciences School of Pharmacy Health Sciences Facility II, Room 629 University of Maryland, Baltimore 20 Penn St. Baltimore, MD 21201 jalem...@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-requ...@gromacs.org. End of gromacs.org_gmx-users Digest, Vol 158, Issue 106 *** -- 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