Pasted

for the whole cube:
    dxy = DerCross(p, 'xy')
    dxz = DerCross(p, 'xz')
    dyz = DerCross(p, 'yz')
 
    dxx = Der2(p, 'x')
    dyy = Der2(p, 'y')
    dzz = Der2(p, 'z')
 
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for the whole cube:
    buffer_dx = Der1(p, 'x')
 
for the whole cube:         
    buffer_dy = Der1(p, 'y')
 
for the whole cube:
    dxy = Der1(buffer_dx, 'y')
    dxz = Der1(buffer_dy, 'z')
    dyz = Der1(buffer_dy, 'z')
 
    dxx = Der2(p, 'x')
    dyy = Der2(p, 'y')
    dzz = Der2(p, 'z')