Hi, If you mean origin_shift as non primitive translation part of space group operations, I can understand what you wrote. I can extend spglib so that the database is accessed from the API. The other option is just to hard code the database in Avogadro's crystallography extension itself. It may be a matter of strategy. If Avogadro may have a chance to use other crystal symmetry libraries in the future, it may be better the later option.
Togo On Thu, Aug 21, 2014 at 6:06 AM, Defusco III, Albert A <defu...@pitt.edu> wrote: > Good afternoon everyone, > > I am working on getting porting the crystallography extension and space group > support into Avogadro 2. What is missing from Avogadro 2 is a look-up of > rotation matrices and origin shift vectors for a given space group. Do you > believe it is possible to extend Sgplib so that I can get these quantities > when specifying just the space group (either Hall symbol/number or > international symbol/number)? > > > Here's what I've done so far > > 1. I have added support for rotation matrices and origin shift vectors in > Avogado2's UnitCell class and added a fillUnitCell method to > crystaltools.cpp. A filled unit cell can then be given the the Spglib > routines for further action. (The rotation matrices and origin shift vectors > are only available if read from a cml file where they have been specified in > <transform3> child nodes of <symmetry>.) > > 2. Once a filled unit cell is generated all AvoSpglib/Spglib routines are > nearly unchanged when ported into Avogadro2. > > > > Here's an example of what I mean. > > int numRotations = get_rotation(int HallNumber, > int rotation[][3][3], > double origin_shift[][3]) > > HallNumber is read as input and rotation and origin_shift are populated on > output.The length of the rotation and origin_shift arrays is numRotations. > > Using the space group "F 4d 2 3 -1d" (#525) there are 192 rotation matrices > and origin shift vectors. > > > > Thanks, > Albert > > > > > ------------------------------------------------------ > Albert DeFusco, Ph.D. > Research Assistant Professor > Technical Director, Center for Simulation and Modeling > University of Pittsburgh > Pittsburgh, PA 15260 > 412-648-3094 > http://www.sam.pitt.edu > -- Atsushi Togo http://atztogo.github.com/ atz.t...@gmail.com ------------------------------------------------------------------------------ Slashdot TV. Video for Nerds. Stuff that matters. http://tv.slashdot.org/ _______________________________________________ Avogadro-devel mailing list Avogadro-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/avogadro-devel
