Title:	Electronic structure of 1D carbyne chains
DNr:	SNIC 2020/13-10
Project Type:	SNIC Small Compute
Principal Investigator:	Maciej Dendzik <dendzik@kth.se>
Affiliation:	Kungliga Tekniska högskolan
Duration:	2020-02-10 – 2021-03-01
Classification:	10304
Keywords:

Abstract

Carbon can be found in a variety of widely-studied allotropes such as fullerene, graphene, or diamond. Recently, carbyne chains, consisting of sp-hybridized carbon atoms, have gained a significant scientific attention due to interesting properties such as extraordinary stiffness and potential applications as a hydrogen storage material [1]. Nevertheless, synthesis of long carbyne chains remains challenging. One of the promising methods seems to be a growth of metalated carbyne chains, in which every carbon pair is separated by a copper atom. This can be achieved by thermal cracking of ethyne molecules on Cu(110) surface [2]. Following this approach, we managed to successfully synthesize metalated carbyne nanowires and performed angle-resolved photoemission spectroscopy (ARPES) and scanning-tunneling microscopy (STM) measurements. However, the measured electronic band structure stays in disagreement with the theoretical calculations [3], likely due to a different crystal structure than expected. In collaboration with a group of Prof. B. Hammer, we found a comprehensive list consisting of ca. 60 potentially-stable structures using a novel approach of atomistic structure learning [4]. With this proposal, we aim at calculating the electronic dispersion and simulating STM images of these candidates using density functional theorem (DFT) to compare the results with our experimental measurements. Large amount of structure candidates requires an access to a high-performance computational facility. The expected results will likely shed new light into the process of carbyne synthesis and benchmark the accuracy of the new machine-learning approach of atomic structure determination. References [1] Liu M. et al., "Carbyne from first principles: Chain of C atoms, a nanorod or a nanorope". ACS Nano, 7, 10075–82 (2013). [2] Sun Q. et al., "Bottom-Up Synthesis of Metalated Carbyne", J. Am. Chem. Soc., 138, 1106−1109 (2016). [3] Tu X. et al., "Cu-metalated carbyne acting as a promising molecular wire", J. Chem. Phys., 145, 244702 (2016). [4] Jørgensen M. et al., "Atomistic structure learning", J. Chem. Phys. 151, 054111 (2019).