The NbP ("40") Structure

Last modified 5 April 2001

You can now

• see the structure from several perspectives;
• examine the structure with an external viewer; or
• download the coordinates of the atoms in these pictures in XYZ format.

When c/a = 2, the atoms in this lattice are on the sites of the face centered cubic lattice. Thus Lu et al. use this lattice for their structural stability studies, and arbitrarily assign this lattice a Strukturbericht designation of "40". This designation is also used by Pettifor et al. Since I want to use this lattice for intermetallic calculations, I will also consider this an fcc-like lattice. However, note that the basis vectors are not written in fcc-like format, but rather written so that the origin is an inversion site.

Note that this lattice has the same structural symmetry as the beta-Sn structure. In fact, both Nb and P sit on beta-Sn sublattices. Thus this structure is to the beta-Sn as the B32 (NaTl) structure is to diamond.

• Prototype: NbP
• Pearson Symbol: tI8
• Strukturbericht Designation: "40" (see above)
• Space Group: I4₁/amd (Cartesian and lattice coordinate listings available)
• Number: 141
• Other Elements with this Structure: PTa
• Primitive Vectors:
  • A₁ = aX
  • A₂ = aY
  • A₃ = ½ a X + ½ a Y + ½ c Z

• Basis Vectors:
  • B₁ = - 1/8 A₁ + 5/8 A₂ + 1/4 A₃ = + 3/4 a Y + 1/8 c Z (Nb)
  • B₂ = + 1/8 A₁ - 5/8 A₂ - 1/4 A₃ = - 3/4 a Y - 1/8 c Z (Nb)
  • B₃ = - 3/8 A₁ - 1/8 A₂ + 3/4 A₃ = + 1/4 a Y + 3/8 c Z (P)
  • B₄ = + 3/8 A₁ + 1/8 A₂ - 3/4 A₃ = - 1/4 a Y - 3/8 c Z (P)

See these vectors in a better notation.

Go back to the Cubic Close Packed Structure page.

Go back to Crystal Lattice Structure page.

Structures indexed by:

• Strukturbericht Designation
• Pearson Symbol
• Space Group
• Prototype