Haeckelites

{{short description|Family of hypothetical carbon allotropes}}{{use British English|date=March 2024}}

file:Haeckelite 8–4.png{{cite journal

| doi = 10.1038/srep17902

| pmid = 26658148

| pmc = 4674713

| title = GaN Haeckelite Single-Layered Nanostructures: Monolayer and Nanotubes

| journal = Scientific Reports

| volume = 5

| pages = 17902

| year = 2015

| last1 = Camacho-Mojica | first1 = Dulce C.

| last2 = López-Urías | first2 = Florentino

| bibcode = 2015NatSR...517902C}}]]

Haeckelites are members of a proposed family of hypothetical carbon allotropes. The carbon atoms would be arranged in a trivalently coordinated structure generated by a periodic arrangement of pentagonal, hexagonal and heptagonal carbon rings. They have not yet been synthesised in the laboratory, but have been the subject of a considerable amount of theoretical work and numerical simulation. They were first proposed by Humberto and Mauricio Terrones and their colleagues in 2000.{{cite journal

| title = New Metallic Allotropes of Planar and Tubular Carbon

| year = 2000

| journal = Physical Review Letters

| volume = 84

| issue = 8

| pages = 1716–1719

| doi = 10.1103/physrevlett.84.1716

| display-authors = etal

| pmid = 11017608

|bibcode = 2000PhRvL..84.1716T

| url = http://sro.sussex.ac.uk/id/eprint/20498/1/PhysRevLett.84.1716.pdf

| last1 = Terrones | first1 = H

| last2 = Terrones | first2 = M

| last3 = Hernandez | first3 = E

| last4 = Grobert | first4 = N

| last5 = Charlier | first5 = J. C.

| last6 = Ajayan | first6 = P. M.

}}