I have never tried it but Inelastica: http://inelastica.sourceforge.net/has routines for converting to a zmatrix from a Cartesian geometry. You could try that.
Kind regards Nick 2013/7/17 Frank Maier <[email protected]> > Hi everyone, > > I currently try to run Siesta using the Z-Matrix input in order to add > more flexible constraints to my simulation. > > But my main problem is the creation of the Z-Matrix. I have up to 100 > Atoms, so building it from hand is nearly impossible. > > I tried the program Aten, which allows me to convert the Cartesian > coordinates to a z-matrix format by maintaining the atom order. The > z-matrix however seems to be broken, at least the following Cartesian > coordinates produced by Siesta are garbage. It also stores all values in > variables and somehow Siesta doesn't accept them as variables. > > I also tried Avogadro and its Gaussian export function which also gives me > a z-matrix, but it reshuffles the atoms and so adding defined constraints > to the angles between specific atoms is not possible any longer. > > > All in all does Siesta also use its own implementation in the Z-Matrix > format (different column order, first three rows require additional > informations, ...) > > > So how do you create your Z-matrix? > What programs can you recommend? > Or have you written your own script to convert xyz to z-matrix and might > share it? > > > Best wishes, > Frank >
