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"direct" fractional coordinates

Posted: Fri Feb 03, 2006 6:59 am
by fabella
I have read the vasp user guide relating to POSCAR and the universal scaling factor. I understand that S scales the primitive lattice vectors and coordinates (if in cartesian). But I am trying to convert the frac. coord. (CONTCAR) to cartesian ... I am familiar with "v2xsf", although this is helpful ... the conversion is not successful when using my own "imprevised" scaling factor because the scaling factor assumed in v2xsf is different.

*The question*
I guess what I am trying to ask is what is the proper scaling factor, ( (?volume?)/(scalar_trip_prod) )^1/3 ?? What is the conversion/relation from fractional to cartesian?

Thank You
W

"direct" fractional coordinates

Posted: Fri Feb 03, 2006 9:00 am
by tjf
Well, you could always do it manually. That's always a good way to make sure you understand what's going on.

Scale factor S, three lattice vectors a, b, c, fractional coordinates x, y, z gives cartesian coordinate vector S*x*a+S*y*b+S*z*c.

"direct" fractional coordinates

Posted: Fri Feb 03, 2006 6:04 pm
by fabella
[quote="tjf"]Well, you could always do it manually. That's always a good way to make sure you understand what's going on.

Scale factor S, three lattice vectors a, b, c, fractional coordinates x, y, z gives cartesian coordinate vector S*x*a+S*y*b+S*z*c.[/quote]