[gmx-users] Another problem with Stimulated Annealing

[Monika Sharma]

Dear All,
While doing SA, I am observing that when i am using steep as option for 
minimization, then the md log file generated takes ref_t as 0K temp 
only, but when i am using md as integratore, the temp for ref_t is taken 
as 375K( temp i gave).. See below... Its quite strange....
+++++++++++++++++++++++++++++++++++++
log file with steep as integrator:
------------------------------------- 
grpopts:
   nrdf:             27419.8      451854
   ref_t:                  0           0
   tau_t:                  0           0
anneal:               Single      Single
ann_npoints:               4           4
ann. times [0]:          0.0         2.0         4.0         6.0
ann. temps [0]:        375.0       350.0       325.0       300.0
ann. times [1]:          0.0         2.0         4.0         6.0
ann. temps [1]:        375.0       350.0       325.0       300.0
   acc:            0           0           0
   nfreeze:           N           N           N
---------------------------------
-++++++++++++++++++++++++++++++++++++++++++++++
log file with md as integrator:
---------------------------------------------------------
grpopts:
   nrdf:             27419.8      301239
   ref_t:                375         375
   tau_t:                0.1         0.1
anneal:               Single      Single
ann_npoints:               4           4
ann. times [0]:          0.0         2.0         4.0         6.0
ann. temps [0]:        375.0       350.0       325.0       300.0
ann. times [1]:          0.0         2.0         4.0         6.0
ann. temps [1]:        375.0       350.0       325.0       300.0
   acc:            0           0           0
   nfreeze:           N           N           N
_---------------------------------------------------------------------------

The mdp file is same for both but only diff is the integrator..
Here is mdp file:
title           =
cpp             = /lib/cpp
define          = -DFLEXIBLE
constraints     = none
integrator      = steep (here the only diff as md)
nsteps          = 5000
dt              = 0.02
init_step       = 0
;langevin dynamics
bd_fric         = 0
ld_seed         = 1993
;minimization
emtol           = 100
emstep          = 1.0
;output control
nstxout         = 10
nstvout         = 10
nstfout         = 10
nstlog          = 10
nstenergy       = 10
nstxtcout       = 10
xtc_precision   = 100
xtc_grps        =
energygrps      =
; Neighbor searching
nstlist         = 10
ns_type         = grid
pbc             = xyz
rlist           = 1.5
; electrostatics
coulombtype     = PME
rcoulomb        = 1.5
epsilon_r       = 1.0
; van der waals params
vdwtype         = cutoff
rvdw            = 2.0
; table params
table-extension = 3
;PME params for ewald calc.
fourierspacing  = 0.15
fourier_nx      = 0
fourier_ny      = 0
fourier_nz      = 0
pme_order       = 4
ewald_rtol      = 1e-5
optimize_fft    = yes
; temperature coupling
tcoupl          = berendsen
tc-grps         = protein non-protein
tau_t           =  0.1     0.1
ref_t           =  375     375
; pressure coupling
pcoupl          = berendsen
pcoupltype      = isotropic
tau_p           = 1.2
compressibility = 4.5e-5
ref_p           = 1.01325
; simulated annealing params
annealing       = single single
annealing_npoints = 4     4
annealing_time  =  0   2    4    6     0    2   4   6
annealing_temp  =  375 350  325  300  375 350  325  300
;velocity generation
gen_vel         = no
gen_temp        = 375
gen_seed        = 1732529
-------------------------------------------------------------------------------------------------------------------
So my ques is that does that really means that SA works with md only, 
not steep. Is it a bug or some reason behind it?? I have not come across 
any... but with md run I am not getting any value. the run is crashing, 
only the steep is showing some output, but that at 0K??
Can someone suggest anything for a succesful SA-MD?
Thanks in advance
Regards, Monika