[gmx-users] NMA Fatal Error

[Yao Yao]

Hi Gmxers,

I am doing a protein NMA with the mdp file like,

===========================================


define          = -DEFLEXIBLE
constraints     = none
integrator      = nm ;
emtol           = 0.00001
emstep          = 0.1
nsteps          = 4000  ; Maximum number of (minimization) steps to perform

; Parameters describing how to find the neighbors of each atom and how to calculate the interactions
nstlist         = 0 ; Frequency to update the neighbor list and long range forces
ns_type         = simple        ; Method to determine neighbor list (simple, grid)
;vdwtype         = switch
vdwtype         = cut-off
rlist           = 0.0   ; Cut-off for making neighbor list (short range forces)
;coulombtype    = PME-switch    ; Treatment of long range electrostatic interactions
coulombtype     = cut-off
;rcoulomb       = 1.2   ; Short-range electrostatic cut-off
rcoulomb        = 0.0
;rvdw           = 1.2   ; Short-range Van der Waals cut-off
rvdw            = 0.0
pme_order       = 4
fourierspacing  = 0.12
fourier_nx  = 0
fourier_ny  = 0
fourier_nz  = 0
optimize_fft    = yes
pbc             = no            
=====================================================
 However, it shows 


"Fatal error:
Constraints present with Normal Mode Analysis, this combination is not supported"

Since I put "Constaints" none, I really do not get it. Can someone help me?

thanks,

Yao