657, a method for estimating tetrahedral bond angles
Edward McNelis, Maureen Blandino
Abstract
Edward McNelis, Maureen Blandino
Abstract
A regular tetrahedron has six spatial angles. The sum of these spatial angles for a tetrahedron with all four groups the same (CA4) is 6 × 109.4712206°. To the nearest degree that value is 657°. For a tetrahedron with one group different (CA3B), there are two different bond angles. The sum of these two angles can be approximated to be 219°, one third of 657°. For a tetrahedron with disubstitution by the same group (CA2B2), the approximate sum involves three different angles: ∠ACA + ∠BCB + 4 ∠ACB = 657°. For a tetrahedron with disubstitution by two different groups (CA2BD), the approximate sum uses four different angles: ∠ACA + ∠BCD + 2 ∠ACB + 2 ∠ACD = 657°. For a tetrahedron with all groups different (CABDE), the approximate sum comes from six angles. Examples of each type are given along with the limitations of the method.
OpenAlex reports 12 citations for this work. Citation counts describe recorded attention and do not establish research quality.
A contribution statement is not available in the OpenAlex record.
Method details are not available in the OpenAlex metadata.
Findings are not separately available in the OpenAlex metadata.
Limitations are not available in the OpenAlex metadata.
Application details are not available in the OpenAlex metadata.
A regular tetrahedron has six spatial angles. The sum of these spatial angles for a tetrahedron with all four groups the same (CA4) is 6 × 109.4712206°. To the nearest degree that value is 657°. For a tetrahedron with one group different (CA3B), there are two different bond angles. The sum of these two angles can be approximated to be 219°, one third of 657°. For a tetrahedron with disubstitution by the same group (CA2B2), the approximate sum involves three different angles: ∠ACA + ∠BCB + 4 ∠ACB = 657°. For a tetrahedron with disubstitution by two different groups (CA2BD), the approximate sum uses four different angles: ∠ACA + ∠BCD + 2 ∠ACB + 2 ∠ACD = 657°. For a tetrahedron with all groups different (CABDE), the approximate sum comes from six angles. Examples of each type are given along with the limitations of the method.
Key concepts: Tetrahedron, Chemistry, Group (periodic table), Bond length, Geometry, Crystallography, Mathematics, Crystal structure