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Next: AVERX (average of operator Up: Input Previous: Input for Molecular dynamics:

Input for geometry optimization:

---------------- top of file: nbc.inM --------------------
NEWT 2.0               (NEWT/BFGS   tolf (a4,f5.2))
0.3 0.3 0.3 0.8        ( 1..3:delta, 4:eta(1=friction zero))
0.3 0.3 0.3 0.8        ( 1..3=0 constraint)
------------------- bottom of file ------------------------

Interpretive comments on this file are as follows.

line 1:
format(a4,f5.2)
MINMOD    Modus of the calculation
 NEWT   Performs geometry optimization with damped Newton scheme according to
  
   where $R^\tau_m$ and $F^\tau_m$ are the coordinate and force at time step $\tau$. When the force has changed its direction from the last to the present timestep (or is within the tolerance TOLF), $\eta_m$ will be set to $1-\eta_m$.
 BFGS   Performs geometry optimization with the variable metric method of BFGS. This option works well when a quadratic approximation is a good approximation to the specific potential surface
TOLF    Force tolerance, determines when geometry optimization stops
line 2:
free format
DELTA(1-3)    x,y,z-delta parameters for damped Newton scheme. Determines speed of motion. Good values must be found for each individual system. They depend on the atomic mass, the vibrational frequencies and the starting point. DELTA(i) = 0 constrains the corresponding i-th coordiante (both in NEWT and BFGS)
ETA    damping (friction) parameter for damped Newton scheme. ETA=1 means no friction, ETA=0 means no speed from previous time steps

>>> line 2:
must be repeated for every atom
end:mini

begin:averx


next up previous contents
Next: AVERX (average of operator Up: Input Previous: Input for Molecular dynamics:

2000-04-11