title: Slippage in stacking of graphene nanofragments induced by spin polarization.
abstract: Spin polarization and stacking are interesting effects in complex molecular systems and are both presented in graphene-based materials. Their possible combination may provide a new perspective in understanding the intermolecular force. The nanoscale graphene structures with zigzag edges could possess spin-polarized ground states. However, the mechanical effect of spin polarization in stacking of graphene nanofragments is not clear. Here we demonstrate the displacement between two stacked rhombic graphene nanofragments induced by spin polarization, using first-principles density-functional methods. We found that, in stacking of two rhombic graphene nanofragments, a spin-polarized stacked conformation with zero total spin is energetically more favorable than the closed-shell stacking. The spin-polarized conformation gives a further horizontal interlayer displacement within 1 angstrom compared with the closed-shell structure. This result highlights that, besides the well-known phenomenologically interpreted van der Waals forces, a specific mechanism dependent on the monomeric spin polarization may lead to obvious mechanical effects in some intermolecular interactions.
authors.affiliation: 1] Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012, People's Republic of China [2] Jilin Provincial Key Laboratory of Applied Atomic and Molecular Spectroscopy (Jilin University), Changchun, 130012, People's Republic of China.
authors.forename: Yanyu
authors.initials: Y
authors.lastname: Lei
authors.affiliation: 1] Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012, People's Republic of China [2] Jilin Provincial Key Laboratory of Applied Atomic and Molecular Spectroscopy (Jilin University), Changchun, 130012, People's Republic of China.
authors.forename: Wanrun
authors.initials: W
authors.lastname: Jiang
authors.affiliation: 1] Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012, People's Republic of China [2] Jilin Provincial Key Laboratory of Applied Atomic and Molecular Spectroscopy (Jilin University), Changchun, 130012, People's Republic of China.
authors.forename: Xing
authors.initials: X
authors.lastname: Dai
authors.affiliation: 1] Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012, People's Republic of China [2] Jilin Provincial Key Laboratory of Applied Atomic and Molecular Spectroscopy (Jilin University), Changchun, 130012, People's Republic of China.
authors.forename: Ruixia
authors.initials: R
authors.lastname: Song
authors.affiliation: 1] Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012, People's Republic of China [2] Jilin Provincial Key Laboratory of Applied Atomic and Molecular Spectroscopy (Jilin University), Changchun, 130012, People's Republic of China.
authors.forename: Bo
authors.initials: B
authors.lastname: Wang
authors.affiliation: 1] Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012, People's Republic of China [2] Jilin Provincial Key Laboratory of Applied Atomic and Molecular Spectroscopy (Jilin University), Changchun, 130012, People's Republic of China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Gao
authors.affiliation: 1] Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012, People's Republic of China [2] Jilin Provincial Key Laboratory of Applied Atomic and Molecular Spectroscopy (Jilin University), Changchun, 130012, People's Republic of China.
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Wang