[gmx-users] vibrational spectra of glucose

[Nilesh Dhumal]

Hello,

I want to  calculate the normal vibrational spectra of PF6 anion.
 After the energy minimization, I found that the structure has lost his
symmetry. It does not have Oh symetry.  I compared this structre with
ab-initio which is not matching.
I have pasted the input file for energy minimzation.
WHy structure is loosing its symmetry or why its not giving proper local
minima.
Nilesh


define                   = -DFLEXIBLE

constraints              = none

integrator               = L-BFGS

nsteps                   = 50000

nbfgscorr                = 50

emtol                    = 0.0001

emstep                   = 0.0001

gen_vel                  = yes

gen-temp                 = 300

nstcomm                  =  1

; NEIGHBORSEARCHING PARAMETERS
; nblist update frequency

nstlist                  =10

; ns algorithm (simple or grid)

ns-type                  = simple

; Periodic boundary conditions: xyz (default), no (vacuum)

; or full (infinite systems only)

pbc                      = no

; nblist cut-off

rlist                    = 0

domain-decomposition     = no

; OPTIONS FOR ELECTROSTATICS AND VDW

; Method for doing electrostatics

coulombtype              = Cut-Off

rcoulomb-switch          = 0

rcoulomb                 = 0

; Dielectric constant (DC) for cut-off or DC of reaction field


; Method for doing Van der Waals

vdw-type                 = Cut-off

; cut-off lengths


rvdw-switch              = 0

rvdw                     = 0