example data file

LAMMPS Description           (1st line of file)

100 atoms         (this must be the 3rd line, 1st 2 lines are ignored)
95 bonds                (# of bonds to be simulated)
50 angles               (include these lines even if number = 0)
30 dihedrals
20 impropers

5 atom types           (# of nonbond atom types)
10 bond types          (# of bond types = sets of bond coefficients)
18 angle types         
20 dihedral types      (do not include a bond,angle,dihedral,improper type
2 improper types             line if number of bonds,angles,etc is 0)

-0.5 0.5 xlo xhi       (for periodic systems this is box size,
-0.5 0.5 ylo yhi        for non-periodic it is min/max extent of atoms)
-0.5 0.5 zlo zhi       (do not include this line for 2-d simulations)

Masses

  1 mass
  ...
  N mass                           (N = # of atom types)

Nonbond Coeffs

  1 coeff1 coeff2 ...
  ...
  N coeff1 coeff2 ...              (N = # of atom types)

Bond Coeffs

  1 coeff1 coeff2 ...
  ...
  N coeff1 coeff2 ...              (N = # of bond types)

Angle Coeffs

  1 coeff1 coeff2 ...
  ...
  N coeff1 coeff2 ...              (N = # of angle types)

Dihedral Coeffs

  1 coeff1 coeff2 ...
  ...
  N coeff1 coeff2 ...              (N = # of dihedral types)

Improper Coeffs

  1 coeff1 coeff2 ...
  ...
  N coeff1 coeff2 ...              (N = # of improper types)

BondBond Coeffs

  1 coeff1 coeff2 ...
  ...
  N coeff1 coeff2 ...              (N = # of angle types)

BondAngle Coeffs

  1 coeff1 coeff2 ...
  ...
  N coeff1 coeff2 ...              (N = # of angle types)

MiddleBondTorsion Coeffs

  1 coeff1 coeff2 ...
  ...
  N coeff1 coeff2 ...              (N = # of dihedral types)

EndBondTorsion Coeffs

  1 coeff1 coeff2 ...
  ...
  N coeff1 coeff2 ...              (N = # of dihedral types)

AngleTorsion Coeffs

  1 coeff1 coeff2 ...
  ...
  N coeff1 coeff2 ...              (N = # of dihedral types)

AngleAngleTorsion Coeffs

  1 coeff1 coeff2 ...
  ...
  N coeff1 coeff2 ...              (N = # of dihedral types)

BondBond13 Coeffs

  1 coeff1 coeff2 ...
  ...
  N coeff1 coeff2 ...              (N = # of dihedral types)

AngleAngle Coeffs

  1 coeff1 coeff2 ...
  ...
  N coeff1 coeff2 ...              (N = # of improper types)

Atoms

  1 molecule-tag atom-type q x y z nx ny nz  (nx,ny,nz are optional -
  ...                                    see "true flag" input command)
  ...                
  N molecule-tag atom-type q x y z nx ny nz  (N = # of atoms)

Velocities

  1 vx vy vz
  ...
  ...                
  N vx vy vz                        (N = # of atoms)

Bonds

  1 bond-type atom-1 atom-2
  ...
  N bond-type atom-1 atom-2         (N = # of bonds)

Angles

  1 angle-type atom-1 atom-2 atom-3  (atom-2 is the center atom in angle)
  ...
  N angle-type atom-1 atom-2 atom-3  (N = # of angles)

Dihedrals

  1 dihedral-type atom-1 atom-2 atom-3 atom-4  (atoms 2-3 form central bond)
  ...
  N dihedral-type atom-1 atom-2 atom-3 atom-4  (N = # of dihedrals)

Impropers

  1 improper-type atom-1 atom-2 atom-3 atom-4  (atom-2 is central atom)
  ...
  N improper-type atom-1 atom-2 atom-3 atom-4  (N = # of impropers)