1
|
Peng J, Zhang S, Refson K, Dove MT. Unique features of the structural phase transition in acetylene showing simultaneous characteristics of reconstructive, displacive and order-disorder. Phys Chem Chem Phys 2023; 25:9909-9924. [PMID: 36946889 DOI: 10.1039/d3cp00400g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/18/2023]
Abstract
We have studied the two phases of the molecular crystal acetylene, C2H2, using calculations of the lattice dynamics by Density Functional Theory methods. together with the use of classical molecular dynamics (MD) simulation methods. The two phases share the same simple face-centred cubic lattice arrangement of the molecular centres of mass, but with different molecular orientations. We show that the higher-temperature phase has lower phonon frequencies and hence higher entropy, giving thermodynamic stability at higher temperature. The calculated lattice dynamics of this phase show instabilities associated with phonons involving pure rotations of the molecules. The MD results show large amplitudes of librational motion in this phase. The MD simulations also showed a potential phase transition to a structure of tetragonal symmetry. The picture that emerges is that the phase transition in acetylene is a very rare example of one that encompasses elements of three types of transition: displacive, order-disorder and reconstructive.
Collapse
Affiliation(s)
- Jie Peng
- College of Physics, Sichuan University, Chengdu, Sichuan 610065, China
| | - Sijie Zhang
- Guizhou University of Engineering Science, Xueyan Road, Bijie, Guizhou, 55170, China
- College of Physics, Sichuan University, Chengdu, Sichuan 610065, China
| | - Keith Refson
- ISIS Facility, Harwell Campus, Chilton, Didcot, OX11 0QX, UK
| | - Martin T Dove
- College of Computer Science, Sichuan University, Chengdu, Sichuan 610065, China.
- School of Mechanical Engineering, Dongguan University of Technology, 1st Daxue Road, Songshan Lake, Dongguan, Guangdong 523000, China
- School of Physical and Chemical Sciences, Queen Mary University of London, Mile End Road, London, E1 4NS, UK.
| |
Collapse
|
2
|
|
3
|
Affiliation(s)
- Kimberly Shuler
- Department of Chemistry, Indiana UniversityPurdue University Indianapolis, 402 North Blackford Street, Indianapolis, Indiana 46202
| | - Clifford E. Dykstra
- Department of Chemistry, Indiana UniversityPurdue University Indianapolis, 402 North Blackford Street, Indianapolis, Indiana 46202
| |
Collapse
|
4
|
Parlinski K, Chapuis G. Calculations of the phonon dispersion curves of C2H2, OC(ND2)2, and Na2CO3 from generic force field. J Chem Phys 1999. [DOI: 10.1063/1.478543] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
5
|
|
6
|
Nelligan WB, LePoire DJ, Brun TO, Kleb R. Inelastic neutron scattering study of the torsional and CCC bend frequencies in the solid n‐alkanes, ethane–hexane. J Chem Phys 1987. [DOI: 10.1063/1.453085] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
7
|
Gamba Z, Bonadeo H. Vibrational intensities of lattice modes and the distributed dipole model: Crystalline acetylene. J Chem Phys 1984. [DOI: 10.1063/1.447521] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
8
|
|
9
|
|
10
|
|
11
|
Filippini G, Gramaccioli CM, Simonetta M. Application of semiempirical atom–atom potentials to crystals of acetylene. J Chem Phys 1980. [DOI: 10.1063/1.440254] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
|
12
|
Whitfield RG, Leroi GE. Raman phonon spectra of partially‐deuterated crystalline ethylenes. J Chem Phys 1978. [DOI: 10.1063/1.436038] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
|
13
|
|
14
|
Sataty YA, Ron A. Lattice vibrations of crystalline benzene. II—Librational modes. J Chem Phys 1976. [DOI: 10.1063/1.433214] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
15
|
|
16
|
Sataty YA, Ron A, Herbstein FH. Carbon tetrafluoride—phase II: Far‐infrared spectrum and crystal structure. J Chem Phys 1975. [DOI: 10.1063/1.430551] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
17
|
Sataty YA, Ron A. Temperature dependence of the far‐infrared spectrum of crystalline carbon dioxide. J Chem Phys 1974. [DOI: 10.1063/1.1681908] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
18
|
|
19
|
|
20
|
|
21
|
|