units update?

Matthias matthia... at psi.ch
Thu Mar 27 07:30:14 UTC 2008


Hi Axel,

you are right, an input keyword cannot be used, but a command line
flag like --codata2006 should work.

Matthias

On Mar 26, 10:15 pm, Axel <akoh... at gmail.com> wrote:
> On Mar 26, 3:48 am, Matthias <matthia... at psi.ch> wrote:
>
> > Hi Axel,
>
> > there are only roughly ten constants which are affected. I would
> > suggest to keep the old CODATA 1998 constants and just to add the new
> > CODATA 2006 constants together with an new input keyword in the GLOBAL
> > section which allows to select the employed data set. The new
>
> good point. one problem. init_physcon is called way before
> the input file is read. i have not been able to find out yet
> whether those factors are used in reading the input. if yes,
> it would result in inconsistent behavior. it may be safer to
> use a command line flag, which is processed before reading input
> and then just re-initialize the values. any suggestions, comments?
>
>
>
> > constants could become the default. In this way everybody can easily
> > check the effect of such a change and the backward compatibility of
> > released versions is achieved.
>
> > Matthias
>
> > On Mar 26, 7:12 am, Teodoro Laino <teodor... at gmail.com> wrote:
>
> > > Hi Axel,
>
> > > The patch is welcome as long as you keep only the fundamental units,
> > > computing the
> > > derived ones.. and anyway the changes should be *tiny* (hopefully
> > > constants should not be changed
> > > toooo much.. ;-) ).. just send the patch..
>
> those things can add up fast, given a large enough problem.
> i just had an "involuntary test" with CPMD and a semingly
> minor change to the bohr/angstrom conversion in the QM/MM
> interface code resulted in a >1kcal/mol change in the (total) energy.
>
> cheers,
>     axel.
>
> > > teo
>
> > > On 25 Mar 2008, at 22:55, Axel wrote:
>
> > > > hi all,
>
> > > > since there seems to be some "spring cleaning" (much appreciated, btw)
> > > > going on
> > > > in the cp2k cvs. one question about conversion factors and fundamental
> > > > constants:
>
> > > > does anybody object if i submit a patch to update the fundamental
> > > > constants
> > > > and conversion factors to CODATA 2006? since this will affect most if
> > > > not all
> > > > regtests it may be worth doing it at a time when everybody is happy
> > > > with the
> > > > code and there are no failing regtests. ...and of course it is one of
> > > > the steps
> > > > towards a release. ;-)
>
> > > > cheers,
> > > >     axel.


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