Modify ConfigurationData.box later or change box origin in gsd file?

[mdeutsc2]

Hi!
I'm writing a custom model (i.e. not using hoomd) which is outputting to gsd files. Our simulation box extends from 0->Lx, 0->Ly, 0->Lz. When setting frame.configuration.box and visualizing, the simulation box extends from -Lx/2 -> Lx/2 (and likewise in other dimensions). I know I can just change the cell origin manually via an affine transformation in Ovito, but is there another way to do this with gsd/python? Thanks!
MWE:

import gsd.hoomd
import numpy as np
gsdfile = gsd.hoomd.open(name = "test.gsd", mode="w")
pos = np.random.rand(10,3)*20
frame = gsd.hoomd.Frame()
frame.particles.N = 10
frame.configuration.box = [20,20,20,0,0,0]
frame.particles.position = pos
gsdfile.append(frame)
gsdfile.flush()
gsdfile.close()

[joaander]

No. The gsd.hoomd specification explicitly requires that the origin is the center of the simulation box. To write a well-formed GSD file with the hoomd specification, you must translate the coordinates before writing.