The ABINIT Users Mailing List ( CLOSED )

["WANG Yuan Xu" <wang.yuanxu@nims.go.jp>]

Dear all,

        When during optimize structre , it have below warning information:

                         findmin : WARNING -
                         The 2nd degree equation has no positive root 
(choice=4).
                          findmin : COMMENT -
                          Will continue, since the new total energy is lower
                           than the old. Take a larger step in the same 
direction.
      Another the optimize not converged even to 200 steps.

why?

ndtset 0 
 kptopt 1
 nshiftk 4
 shiftk 0.5 0.5 0.5
       0.5  0.0 0.0
       0.0  0.5 0.0
       0.0  0.0 0.5
 ngkpt   4 4 4
acell 7.54 7.54 7.63 
angdeg 90 90 90
 xred
 0.0000000000    0.0000000000    0.0040000000
 0.5000000000    0.5000000000    0.5100000000
 0.0000000000    0.5000000000    0.5000000000
 0.5000000000    0.0000000000    0.5000000000
 0.5000000000    0.5000000000    0.0000000000
 optcell  0  
 ionmov   3 
 ntime    200 
 ecutsm    0.5
 localrdwf 1 
 ntypat   4 
 znucl    56 22 8 8
 natom 5
 typat 1 2 3 3 4
 ixc 3 
 ecut 40 
 nstep  60
 toldfe  1.0d-6
 tolmxf 5.0d-4


Best


WANG Yuan Xu
National Institute for Materials Science
Computational Materials Science Center
Namiki 1-1, Tsukuba 305-0044, Japan
Phone +81-29-8513354-8092; Fax +81-29-8541207
wang.yuanxu@nims.go.jp
2004-09-30