Animation loop was returning to frame 1 instead of frame 0, and has now been fixed.
The arc writer also gave the wrong Cartesian coordinates for lattices rotated away from gdis's default, so matrix for calculating atom coordinates should be generated from arc's lattice parameters (pbcs).
Animation loop was returning to frame 1 instead of frame 0, and has now been fixed. The arc writer also gave the wrong Cartesian coordinates for lattices rotated away from gdis's default, so matrix for calculating atom coordinates should be generated from arc's lattice parameters (pbcs).