CCL: AMBER PBC box alignment

["David A. Case" <case++scripps.edu>]

 Sent to CCL by: "David A. Case" [case:_:scripps.edu]
 On Sat, Jul 21, 2007, Jun Cui juc9+]*[pitt.edu wrote:
 >
 >
 > Does amber 9 need the periodic box to be parallel to the xy, yz, and xz
 > planes?
 Amber supports general triclinic unit cells, but the "a" axis must be
 along
 the x direction, and the plane containing "a" and "b" must
 be in the xy plane.
 (If the unit cell is a rectangular parallelopiped, this implies that box edges
 are parallel to xy, yz and xz.)  I don't know of a simple code that will do
 the conversion, however.
 ....dave case