GROMACS version: 2020.1 for Ubuntu
GROMACS modification: No
Hi,
I am having an issue with the freeze groups functionality. I am simulating two proteins in water. I want to freeze the position of the larger of the two proteins. When I use grompp to set up the production run:
gmx grompp -f md-equilibration/md.mdp -c pr-equilibration/pep_actin_pr.gro -r pr-equilibration/pep_actin_pr.gro -p common/pep.top -o md-equilibration/pep_actin_md.tpr -n system.ndx -maxwarn 2
It produces a tpr file but this is the output of the command:
Back Off! I just backed up md-equilibration/pep_actin_md.tpr to md-equilibration/#pep_actin_md.tpr.3#
free(): invalid next size (fast)
Aborted (core dumped)
That last part is concerning. When I try to use mdrun with this tpr file I end up with a segmentation fault. Here is my mdp file (cannot attach because new user…):
integrator = md
dt = 0.002
tinit = 0 ; ps
nsteps = 150000000 ; 300 ns
nstxout = 10000
nstvout = 10000
nstlog = 1000
nstenergy = 1000
nstxtcout = 1000
nstlist = 10
ns_type = grid
vdwtype = Cut-off
optimize_fft = yes
fourierspacing = 0.125
pme_order = 6
ewald_rtol = 1e-5
tcoupl = v-rescale
tc-grps = System ;Protein_chain_A Protein_chain_B NA SOL
tau_t = 0.1 ;0.1 0.1 0.1
ref_t = 300 ;300 300 300
Pcoupl = berendsen
pcoupltype = isotropic
tau_p = 2
compressibility = 0.45e-4
ref_p = 1.0
gen_vel = yes
gen_temp = 300
gen_seed = 173529
constraints = h-bonds
cutoff-scheme = Verlet
vdw-modifier = force-switch
rlist = 1.2
rvdw = 1.2
rvdw-switch = 1.0
coulombtype = PME
rcoulomb = 1.2
DispCorr = no
; FREEZING ACTIN GROUPS COORDINATES
freezegrps = Protein_chain_A Protein_chain_B NA SOL
freezedim = Y Y Y N N N N N N N N N
I have also tried listing the tc-grps explicitly without using the group System and I get a similar error (or a seg fault). It is also worth mentioning that my energy minimization and pressure equilibration steps without freezing any groups works without error. And I can start a production simulation without error if I remove the freeze groups sections from the above mdp file. That leads me to believe this feature is explicitly the reason for the errors I am receiving. I am unsure why this is creating an issue.
Thank you for any help,
Brian