[Wien] same calculation on different machines

[Peter Blaha]

I would call these two calculations as "equal".
If you want them to coincide even better, you must continue with the scf
cycle and put a thighter convergence criterium.

> I notice that calculation results from different machines with exactly same
> inputs are slightly different, but very close. What is the maximum
> difference we can have in a good calculation.
>
> e.g.  in "Ta.outputm", the last few lines are showing:
> >From machine1:
> :DTO001: TOTAL   DIFFERENCE CHARGE**2 IN SPHERE  1 =  0.0000477
>
> :DIS  :  CHARGE DISTANCE       0.0000477
>
>  QMIX5:
>         MAXMQ =     165   MAXMIX =      4235
>
>        BROYD MIXING SCHEME WITH 0.400
>        CHARGES OF MIXED CHARGE DENSITY
> :CTO  : TOTAL   INTERSTITIAL CHARGE=  2.1360469
> :CTO001: TOTAL   CHARGE IN SPHERE  1 = 70.8639532
>
>
> :ENE  : ********** TOTAL ENERGY IN Ry =       -31252.208215
>
> >From Machine 2:
>
> :DTO001: TOTAL   DIFFERENCE CHARGE**2 IN SPHERE  1 =  0.0000490
>
> :DIS  :  CHARGE DISTANCE       0.0000490
>
>  QMIX5:
>         MAXMQ =     165   MAXMIX =      4235
>
>        BROYD MIXING SCHEME WITH 0.400
>        CHARGES OF MIXED CHARGE DENSITY
> :CTO  : TOTAL   INTERSTITIAL CHARGE=  2.1358511
> :CTO001: TOTAL   CHARGE IN SPHERE  1 = 70.8641489
>
>
> :ENE  : ********** TOTAL ENERGY IN Ry =       -31252.208226
>
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>


                                      P.Blaha
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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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