[gmx-users] DPPC/DPPE minim.mdp

[Poncho Arvayo Zatarain]

Hello, i want to simulate a 128 DPPC molecule, 3655 water molecules  but with 25% of DPPE. I replace de 25% of 128 DPPC molecules with DPPE and i'ḿ using the same forcefield and topology reported by Lemkul in his KALP15 in DPPC tutorial. When i want to minimize the energy i use the command line: gmx grompp -f minim.mdp -c dppc-dppe128.pdb -p topol_dppc.top -o em.tp but the following error appears: Input/output error: minim.mdp. How can i solve it? Is correct to use the same forcefield and topology? I'm using Gromacs 5.0.4. This in my minim.mdp file 
; minim.mdp - used as input into grompp to generate em.tpr
integrator	= steep		; Algorithm (steep = steepest descent minimization)
emtol		= 1000.0  	; Stop minimization when the maximum force < 1000.0 kJ/mol/nm
emstep      = 0.01      ; Energy step size
nsteps		= 50000	  	; Maximum number of (minimization) steps to perform

; Parameters describing how to find the neighbors of each atom and how to calculate the interactions
nstlist		    = 1		    ; Frequency to update the neighbor list and long range forces
cutoff-scheme   = Verlet
ns_type		    = grid		; Method to determine neighbor list (simple, grid)
coulombtype	    = PME		; Treatment of long range electrostatic interactions
rcoulomb	    = 1.0		; Short-range electrostatic cut-off
rvdw		    = 1.0		; Short-range Van der Waals cut-off
pbc		        = xyz 		; Periodic Boundary Conditions (yes/no)