A247446 Decimal expansion of Pi*sqrt(3)/16.

3, 4, 0, 0, 8, 7, 3, 8, 0, 7, 9, 3, 9, 1, 5, 8, 4, 6, 9, 8, 6, 3, 8, 9, 6, 7, 3, 3, 0, 7, 9, 0, 4, 1, 9, 9, 8, 0, 3, 2, 6, 2, 4, 2, 1, 5, 1, 7, 3, 8, 8, 8, 5, 7, 9, 1, 9, 3, 5, 3, 4, 2, 5, 3, 8, 5, 2, 7, 3, 0, 9, 6, 4, 6, 1, 1, 9, 1, 3, 5, 3, 1, 9, 0, 7, 7, 3, 4, 3, 5, 2, 8, 9, 7, 6, 1, 2, 8, 1, 6, 6, 0, 5, 4, 1, 7

Offset: 0

Author

Stanislav Sykora, Sep 29 2014

Keywords

• nonn
• cons
• easy

Comments

The atomic packing factor (APF) of the diamond cubic crystal lattice and the smallest APF among all crystallographic lattices filled by spheres of the same diameter. The APF of the body-centered-cubic (bcc) lattice packed with spheres of the same diameter is twice this value (see Examples). For other crystal lattices, see the cross-refs.

Examples

			0.340087380793915846986389673307904199803262421517388857919353425385273...
APF of the bcc lattice packed with spheres of the same diameter:
0.680174761587831693972779346615808399606524843034777715838706850770546...
		

Links

• Stanislav Sykora, Table of n, a(n) for n = 0..2000
• Steve Sque, Structure of Diamond (adapted from 2005 thesis)
• Wikipedia, Diamond cubic
• Wikipedia, Atomic packing factor
• Index entries for transcendental numbers

Crossrefs

Cf. APF's of other crystal lattices: A093825 (hcp,fcc), A019673 (simple cubic).

Programs

Mathematica

RealDigits[Pi*Sqrt[3]/16,10,120][[1]] (* Vaclav Kotesovec, Oct 04 2014 *)

PARI

Pi*sqrt(3)/16