monoclinic structure

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1

Dear all

I am trying to calculate lattice parameters of B19’ NiTi phase. In several papers, lattice parameters of B19’ phase are represented as following;

a=4.622
b=2.885
c=4.120
beta=96.8 deg

Conventional coordinates of B19’ NiTi phase are reported which are

Ti 1:(0, 0, 0)
Ti 2:(0.558, 0.5, 0.055)
Ni 1:(0.472, 0, 0.580)
Ni 2:(0.086, 0.5, 0.475)

According to the lammps manual the three edge vectors are given by a = (xhi-xlo,0,0); b = (xy,yhi-ylo,0); c = (xz,yz,zhi-zlo), and xz=c*cos(beta).

my question is that can I use these parameters as a1, a2, a3 in lattice custom command?

using above coordinates, I created a lammps code to calculate lattice coordinates of monoclinic structure.

lattice custom 1 a1 4.622 0.0 0.0 a2 0.0 2.885 0.0 a3 -0.486 0.0 4.120

I am still not sure how lammps parameters are defined, especially lo and hi values(i.e xhi, xlo). what is xlo and xhi values? Can I use xlo,ylo,zlo=0.0?

please guide me…

Thanks

2

Dear all

I am trying to calculate lattice parameters of B19’ NiTi phase. In several papers, lattice parameters of B19’ phase are represented as following;

a=4.622
b=2.885
c=4.120
beta=96.8 deg

Conventional coordinates of B19’ NiTi phase are reported which are

Ti 1:(0, 0, 0)
Ti 2:(0.558, 0.5, 0.055)
Ni 1:(0.472, 0, 0.580)
Ni 2:(0.086, 0.5, 0.475)

According to the lammps manual the three edge vectors are given by a = (xhi-xlo,0,0); b = (xy,yhi-ylo,0); c = (xz,yz,zhi-zlo), and xz=c*cos(beta).

my question is that can I use these parameters as a1, a2, a3 in lattice custom command?

using above coordinates, I created a lammps code to calculate lattice coordinates of monoclinic structure.

lattice custom 1 a1 4.622 0.0 0.0 a2 0.0 2.885 0.0 a3 -0.486 0.0 4.120

I am still not sure how lammps parameters are defined, especially lo and hi values(i.e xhi, xlo). what is xlo and xhi values? Can I use xlo,ylo,zlo=0.0?

please guide me…

This is all explained in the manual and in many discussions on this mailing list. Please keep reading and don’t guess.

Axel

3

More specifically, see the lattice doc page and the
Section howto 6.12 on triclinic boxes which has
info on different ways to represent a simulation box
and lattices.

Steve