[Wien] minimization of positions
Hem Chandra Kandpal
kandpal at uni-mainz.de
Tue Jan 3 12:08:15 CET 2006
Dear Sir,
Thank you for your kind help.
I am going to restart using your suggestions.
regards
hem
On Sun, 1 Jan 2006, Peter Blaha wrote:
> How big are the forces for your initial structure ?
>
> How many geometry steps were performed ?
>
> grep :ENE *mini
> grep :FOR00x *mini
>
> If your initial positions are really that bad (and thus the forces are
> very big), it might be that you need smaller values in case.inM (or that
> you need to restart by removing case.tmpM).
>
> Sometimes atoms want to come closer than allowed with the selected RMTs.
> In these cases you must restart with smaller spheres (Sometimes these
> messages appear only at an intermediate step, then you can ignore them).
>
> With a recent WIEN2k version you can use all convergence criteria at once:
>
> runsp -ec 0.0001 -cc 0.0001 -fc 1 -I -i 60
>
>
> >
> > Dear Wien Users,
> >
> > I am trying to optimize the positions of a ternary system.
> > Below I am giving full detail about that system
> > system is
> > MnCoSn ( a = 4.258 Ang, c = 5.36) (Space group 186)
> > Mn (0 0 1/4)
> > Co (1/3 2/3 0.44=z1)
> > Ge (1/3 2/3 0.06=z2)
> >
> > To optimize the z parameters of Co (z1) and Ge (z2) atoms.
> > I am using PORT option as given in the manual.
> >
> > Let me tell you one thing, my system positions are far away from the
> > solution, because this system is only reported as Ni2In structure type
> > (space group 194) and I would like to minimize it in LiGaGe structure
> > type (space group 186). In space group 186 each atom will have their
> > own positions as given above. These positions I took from other ternary system.
> >
> > I follow this procedure
> > 1. runsp_lapw -ec 0.0001 -i 40 -r 15
> > 2. runsp_lapw -cc 0.001 -i 40 -r 15
> > 3. runsp_lapw -fc 1 -i 40 -r 15
> >
> > then I Have edited case.inM file like this
> >
> > PORT 2.0 # PORT/NEWT; tolf (geom.opt. stops when F<;tolf)
> > 0.0 0.0 1.0 3.0 # Mn
> > 0.0 0.0 1.0 1.0 # Co #PORT: delta1,2,3=precond., 4:Bondorder
> > 0.0 0.0 1.0 1.0 # Sn
> >
> > when I start with ---> min -NI -i 4 -s 1 -j 'runsp_lapw -I -i 40 -fc 1.0 '
> >
> > It is running and my forces are very far from force criterion and at the
> > end in my dayfile it writes line like this -->
> >
> > ##########################dayfile
> > :ENERGY convergence: 0 0 .0000525000000000
> > :CHARGE convergence: 0 0.0000 .0002335
> >
> > > stop
> > > mini (01:07:58) 0.070u 0.015s 0:00.08 100.0% 0+0k 0+0io 0pf+0w
> > :WARNING, CURVATURE CONDITION FAILED
> > :WARNING, S.Y WAS -0.304898817526764
> > :WARNING: Step size reduced due to overlapping spheres -- check RMT
> > :WARNING: Step size reduced due to overlapping spheres -- check RMT
> > ############################################################
> >
> > my forces are looking like --->
> >
> > ###########################################
> > :ENE : ********** TOTAL ENERGY IN Ry = -34925.629006
> >
> > TOTAL FORCE IN mRy/a.u. = |F| Fx Fy Fz
> > :FOR001: 1.ATOM 114.688 0.000 0.000 114.688
> > :FOR002: 2.ATOM 992.576 0.000 0.000 -992.576
> > :FOR003: 3.ATOM 1776.551 0.000 0.000 1776.551
> >
> > #############################################
> >
> > Can anyone please explain me, what is the process to do such kind of
> > minimization, am I doing the right way? and what to do if I see
> > with iterations, forces are increasing on each atom and vice versa.
> >
> > What is the criterion for choosing RMT values for such complicated
> > (I mean without knowing exact positions) systems.
> >
> >
> >
> > ############################
> >
> > In the begining, I thought, I am doing some thing wrong with
> > my calculations. then I tried to check these steps (as given above for
> > minimization) on a well reported system
> >
> > example LiGaGe (a = 4.175, c = 6.783 Ang)
> > Li (0 0 1/4)
> > Ga (1/3 2/3 0.06)
> > Ge (1/3 273 0.44)
> >
> > and it coverges without any error, in my dayfile
> >
> > #############################################
> > > stop
> > > mini (16:09:10) 0.029u 0.009s 0:00.04 50.0% 0+0k 0+0io 0pf+0w
> >
> > > stop forces small, minimization stopped
> >
> > > relaxation steps summarized in LiGaGe_opt.scf_mini
> >
> > > relaxed structure and results in LiGaGe_opt.struct, scf, clmsum
> > ##############################################
> >
> >
> > and in my third optimized scf file :
> >
> > #############################################
> > :ENE : ********** TOTAL ENERGY IN Ry = -16202.425763
> >
> > TOTAL FORCE IN mRy/a.u. = |F| Fx Fy Fz
> > :FOR001: 1.ATOM 1.242 0.000 0.000 1.242
> > :FOR002: 2.ATOM 2.019 0.000 0.000 -2.019
> > :FOR003: 3.ATOM 0.428 0.000 0.000 0.428
> >
> > ############################################
> >
> >
> > If it is working for such stabilized system it should work for
> > my unrelaxed system. I think somewhere I missing some points.
> >
> > What would be the good option for such system either PORT
> > or NEWT. Can I also edit DELTA values (range???) in my
> > case.inM file with PORT option like Prof. Blaha expalined
> > for NEWT in FAQ of Wien.
> >
> >
> > I will be grateful for your kind reply and help
> >
> > Thanking you in advance
> > hem kandpal (mainz)
> > _______________________________________________
> > Wien mailing list
> > Wien at zeus.theochem.tuwien.ac.at
> > http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien
> >
>
>
> P.Blaha
> --------------------------------------------------------------------------
> Peter BLAHA, Inst.f. Materials Chemistry, TU Vienna, A-1060 Vienna
> Phone: +43-1-58801-15671 FAX: +43-1-58801-15698
> Email: blaha at theochem.tuwien.ac.at WWW: http://info.tuwien.ac.at/theochem/
> --------------------------------------------------------------------------
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