[lammps-users] triclinic geometry and data file

Not sure what you are asking. You can look at the 4.12
doc page which explains triclinic boxes in LAMMPS and
how to convert from one representation to another. LAMMPS
requires the xy, yz, xz factors as input, so you have to
supply them.

Steve

Hello David,

The transformations from (a,b,c alpha,beta,gamma) to ( lx,ly,lz,xy,xz,yz) are:

a^2 = lx^2
b^2 = ly^2 + lz^2
c^2 = lz^2 + xz^2 + yz^2
cos(alpha) = xy*xz + ly*yz/b*c
cos(beta) = xz/c
cos(gamma) = xy/b

Be careful with some arithmetic here!

cos(alpha) = (xy*xz + ly*yz)/b*c

The expression for b^2 is also wrong. For the definitive formulae, see:

http://lammps.sandia.gov/doc/Section_howto.html#4_12