From: Fabian Dortu <fabian.dortu@wa...>  20020912 12:12:37

On Thu, 20020912 at 13:34, E.L. Willighagen wrote: > On Friday 06 September 2002 13:11, Fabian Dortu wrote: > > Ok now, suppose we have a *cartesian* referential x,y,z. Actually it is > > the referential used in Jmol. > > > > **The base vectors given in CP are the base vectors in this referential. > > These base vectors are *absolute*. I mean that the orientation of the > > unit cell is fixed. > > The atomic positions can be loaded either in *cartesian* coordinate or > > in *crystallographic* coordinate (=reduced coordinate of the base > > vectors). > > > > **Now suppose that the base vectors are given in the nation > > a,b,c,alpha,beta,gamma. The unit cell is no more fixed in space. If you > > want to fix it you have to make 2 hypothesis. For instance: > > > > a is parallel to x. > > b is in plane (xy). > > > > If you don't fix the unit cell, you can only give the atoms in > > *crystallographic* coordinate. If you fix the unit cell in the > > referential then you can also give the *cartesian* coordinate. > > Have you seen that the program I wrote based on Jmol 1 contains > code to do this? > > Egon > OOups, no, I didn't check actually. I will have a look. Fabian  Contrary to popular belief, Unix is user friendly. It just happens to be selective about who it makes friends with. Dave Parnas ********** Fabian Dortu Collegeberg 16 .~. 3000 Leuven /V\ Belgium /( )\ ^^^^ Phone : 32475599268 emails : Fabian.Dortu@... Fabian.Dortu@... *********************************************** 