[gmx-users] semiisotropic pressure coupling error

[Oguz Gurbulak]

Dear Gromacs Users,

When I used semiisotropic pressure coupling, I got this error message

"Fatal error:
The Y-size of the box (4.200315) times the triclinic skew factor (1.000000)
is smaller than the number of DD cells (3) times the smallest allowed cell
size (1.400000)"


Could you please help me to solve this error ?


Kind regards.


**** MDP FILE ****

; Run parameters
integrator    = md        ; leap-frog integrator
nsteps        = 5000000    ;
dt            = 0.002        ;

; Output control
nstxout        = 2000        ;
nstvout        = 2000        ;
nstenergy    = 2000        ;
nstlog        = 2000        ;

; Bond parameters
constraint_algorithm   = lincs        ;
constraints           = all-bonds  ;
lincs_iter           = 1     ;
lincs_order           = 4       ;


; Neighbor searching
cutoff-scheme   = Verlet
rlist            = 1.4       ;
ns_type        = grid
nstlist        = 10        ;
nstcomm         = 100

; Electrostatics
coulombtype        = PME    ;
rcoulomb        = 1.4    ;
pme_order           = 4
fourierspacing      = 0.16
ewald-rtol          = 1e-5

; Dispersion correction
DispCorr    = EnerPres      ;


; Van der Waals
vdwtype = cutoff
rvdw = 1.4    ;


; Temperature coupling is on
tcoupl        = V-rescale            ;
tc-grps        = ABC SOL            ;
tau_t        = 0.1    0.1                ;
ref_t        = 302.7 302.7                ;


; Pressure coupling is on
pcoupl        = berendsen        ; Pressure coupling on in NPT
pcoupltype    = semiisotropic            ;
tau_p        = 2.0                    ;
ref_p        = 50.0    1.0                ;
compressibility = 4.5e-5    4.5e-5    ;


; Periodic boundary conditions
pbc        = xyz            ; 3-D PBC


; Velocity generation
continuation    = no        ;
gen_vel        = yes        ;
gen_temp    = 302.7        ;
gen_seed    =  -1        ;