K<sub>2</sub>N<sub>2</sub>中一维氮链的压力诱导聚合

陈磊; 张云; 陈雨轩; 魏群; 张美光

doi:10.11858/gywlxb.20240719

Pressure-Induced Polymerization of One-Dimensional Nitrogen Chains in K₂N₂

doi: 10.11858/gywlxb.20240719

1.
College of Physics and Optoelectronic Technology, Baoji University of Arts and Sciences, Baoji 721013，Shaanxi，China
2.
School of Physics, Xidian University, Xi’an 710071, Shaanxi, China

Funds: National Natural Science Foundation of China (11964026)；Natural Science Basic Research Program of Shaanxi (2023-JC-YB-021, 2024JC-YBMS-048)

More Information

Author Bio:
CHEN Lei (1983－), male, doctor, associate professor, major in high pressure materials and structures. E-mail: stonley@163.com

Corresponding author: ZHANG Meiguang (1981－), male, doctor, professor, major in high pressure materials and structures. E-mail: zhmgbj@126.com

摘要

摘要: 采用先进的粒子群晶体结构搜索方法对K₂N₂在0～150 GPa压强范围内进行晶体结构预测，结果表明，K₂N₂的基态稳定相为单斜C2/m结构，且在1.7、3.6和122 GPa压强下的结构分别为Na₂N₂型、Cmmm、C2/c。体积随压强的变化关系显示C2/m→Na₂N₂型、Na₂N₂型→Cmmm和Cmmm→C2/c这3个相变均为一级相变，对应的体积坍塌分别为14.4%、22.5%和4.0%。在K₂N₂高压相变过程中，K原子的配位数从5增加到10，并伴随着N-N成键性质的变化，即从基态C2/m结构中的准分子N＝N双键聚合为高压C2/c相中的N―N单键链。C2/m、Na₂N₂型、Cmmm相表现出金属性，而高压C2/c相表现出半导体（带隙为2.0 eV）性质。电子结构计算和电子局域函数分析表明，K₂N₂的高压结构相变来源于高压下K-p孤对电子的激活及其与N原子的成键。
- 高压 /
- K₂N₂ /
- 结构预测 /
- 结构相变 /
- 电子结构
Abstract: The crystal structure prediction of K₂N₂ in the pressure range of 0–150 GPa using an advanced particle swarm crystal structure search method was conducted. The results show that the stable ground state phase of K₂N₂ is a monoclinicC2/mstructure, and three high-pressure structures including Na₂N₂-type,Cmmm, andC2/care identified at pressures of 1.7, 3.6, 122 GPa, respectively. The volume dependence on pressure shows that the three phase transitions, i. e.,C2/m→Na₂N₂-type, Na₂N₂-type→Cmmm, andCmmm→C2/c, are all first order phase transitions, corresponding to volume collapses of 14.4%, 22.5%, and 4.0%, respectively. During the high pressure phase transitions of K₂N₂, the coordination number of K atom increases from 5 to 10, and a change in the nature of the N-N bonding from N＝N dimmer in the ground state ofC2/mstructure to N―N single bond chain in the high-pressureC2/cphase is accompanied. The high-pressureC2/cphase exhibits semiconducting properties with a band gap of 2.0 eV, whileC2/m, Na₂N₂-type, andCmmmphases have metallic behaviors. Electronic structure calculation and electron-localized function analysis indicate that the high-pressure structural phase transition of K₂N₂ is due to the K-plone-pair electrons activation and their participation in bonding with N atoms under high pressure.
- high pressure /
- K₂N₂ /
- structure predictions /
- phase transitions /
- electronic structures

HTML全文

Figure 1. Crystal structure of C2/m, Na₂N₂-type, Cmmm, and C2/c phases (The large and small spheres represent K and N atoms, respectively.)

下载: 全尺寸图片幻灯片

Figure 2. Calculated phonon curves of the C2/m (a), Na₂N₂-type (b), Cmmm (c), and C2/c (d) phases at selected pressure points

下载: 全尺寸图片幻灯片

Figure 3. (a)–(b) Enthalpy differences of the different predicted structures relative to the Na₂N₂-type structure under pressure;(c)–(d) pressure dependence of the volume per f. u. of each structure for K₂N₂

下载: 全尺寸图片幻灯片

Figure 4. Total and site projected DOSs of C2/m (a), Na₂N₂-type (b), Cmmm (c), and C2/c (d) phases

下载: 全尺寸图片幻灯片

Figure 5. Projected weights of N-p orbitals in the band structures of C2/m (a), Na₂N₂-type (b), Cmmm (c), and C2/c phases (d) (The Fermi level is indicated by horizontal lines and the black solid lines denote the energy structures of each phase of K₂N₂)

下载: 全尺寸图片幻灯片

Figure 6. Contours of ELF for the C2/m on the (010) plane (a), Na₂N₂-type on the (010) plane (b), Cmmm on the (100) plane (c), and C2/c on the (010) plane (d)

下载: 全尺寸图片幻灯片

Table 1. Optimized structural parameters of the C2/m, Na₂N₂-type, Cmmm, and C2/c phases of K₂N₂

Phase	Pressure/GPa	Lattice parameters	d_N-N/Å	Atomic fractional coordinates
C2/m	0	a = 7.562 Å, b = 3.912 Å, c = 10.923 Å, α = γ = 90°, β= 134.955°	1.192	K 4i (0.613, 0, 0.260) N 4i (0.519, 0, 0.456)
Na₂N₂-type	2.5	a = 3.326 Å, b = 4.375 Å, c = 5.694 Å, α = β = γ = 90°	1.220	K1 1e (0, 0.500, 0) K2 1c (0, 0, 0.500) N 2t (0.500, 0.500, 0.393)
Cmmm	20.0	a = 6.896 Å, b = 5.104 Å, c = 2.855 Å, α = β = γ = 90°	1.254	K 4g (0.694, 0, 0) N 4j (0, 0.877, 0.500)
C2/c	135.0	a = 6.971 Å, b = 4.099 Å, c = 4.510 Å, α = γ = 90°, β= 81.342°	1.474, 1.373	K 8f (0.669, 0.909, 0.198) N 8f (0.041, 0.887, 0.102)

下载: 导出CSV

Table 2. Calculated Bader charges of K and N atoms in C2/m, Na₂N₂-type, Cmmm, and C2/c phases

Phase	Pressure/GPa	Atom	Charge value/e	Charge transfer/e
C2/m	0	K N	8.509 (×2) 5.491 (×2)	+0.491 −0.491
Na₂N₂-type	2.5	K1 K2 N	8.407 8.303 5.645 (×2)	+0.593 +0.697 −0.645
Cmmm	20.0	K N	8.310 (×2) 5.690 (×2)	+0.690 −0.690
C2/c	135.0	K N	8.377 (×2) 5.623 (×2)	+0.623 −0.623

下载: 导出CSV

参考文献(46)

[1]	PIERSON H O. Handbook of refractory carbides and nitrides: properties, characteristics, processing and applications [M]. Westwood: Noyes, 1996.
[2]	HORVATH-BORDON E, RIEDEL R, ZERR A, et al. High-pressure chemistry of nitride-based materials [J]. Chemical Society Reviews, 2006, 35(10): 987–1014. doi: 10.1039/b517778m
[3]	CHRISTE K O. Polynitrogen chemistry enters the ring: a cyclo- ${{\mathrm{N}}_5^- }$ anion has been synthesized as a stable salt and characterized [J]. Science, 2017, 355(6323): 351. doi: 10.1126/science.aal5057
[4]	LANIEL D, WECK G, LOUBEYRE P. Direct reaction of nitrogen and lithium up to 75 GPa: synthesis of the Li₃N, LiN, LiN₂, and LiN₅ compounds [J]. Inorganic Chemistry, 2018, 57(17): 10685–10693. doi: 10.1021/acs.inorgchem.8b01325
[5]	YAO Y S, ADENIYI A O. Solid nitrogen and nitrogen-rich compounds as high-energy-density materials [J]. Physica Status Solidi (B), 2021, 258(6): 2000588. doi: 10.1002/pssb.202000588
[6]	EREMETS M I, GAVRILIUK A G, TROJAN I A, et al. Single-bonded cubic form of nitrogen [J]. Nature Materials, 2004, 3(8): 558–563. doi: 10.1038/nmat1146
[7]	EREMETS M I, GAVRILIUK A G, TROJAN I A. Single-crystalline polymeric nitrogen [J]. Applied Physics Letters, 2007, 90(17): 171904. doi: 10.1063/1.2731679
[8]	GREGORYANZ E, GONCHAROV A F, SANLOUP C, et al. High P-T transformations of nitrogen to 170 GPa [J]. The Journal of Chemical Physics, 2007, 126(18): 184505. doi: 10.1063/1.2723069
[9]	ZHANG L J, WANG Y C, LV J, et al. Materials discovery at high pressures [J]. Nature Reviews Materials, 2017, 2(4): 17005. doi: 10.1038/natrevmats.2017.5
[10]	MEDVEDEV S A, TROJAN I A, EREMETS M I, et al. Phase stability of lithium azide at pressures up to 60 GPa [J]. Journal of Physics: Condensed Matter, 2009, 21(19): 195404. doi: 10.1088/0953-8984/21/19/195404
[11]	EREMETS M I, POPOV M Y, TROJAN I A, et al. Polymerization of nitrogen in sodium azide [J]. The Journal of Chemical Physics, 2004, 120(22): 10618–10623. doi: 10.1063/1.1718250
[12]	ZHU H Y, ZHANG F X, JI C, et al. Pressure-induced series of phase transitions in sodium azide [J]. Journal of Applied Physics, 2013, 113(3): 033511. doi: 10.1063/1.4776235
[13]	ZHOU M, LIU S J, DU M R, et al. High-pressure-induced structural and chemical transformations in NaN₃ [J]. The Journal of Physical Chemistry C, 2020, 124(37): 19904–19910. doi: 10.1021/acs.jpcc.0c04107
[14]	JI C, ZHANG F X, HOU D B, et al. High pressure X-ray diffraction study of potassium azide [J]. Journal of Physics and Chemistry of Solids, 2011, 72(6): 736–739. doi: 10.1016/j.jpcs.2011.03.005
[15]	JI C, ZHENG R, HOU D B, et al. Pressure-induced phase transition in potassium azide up to 55 GPa [J]. Journal of Applied Physics, 2012, 111(11): 112613. doi: 10.1063/1.4726212
[16]	WANG Y, BYKOV M, CHEPKASOV I, et al. Stabilization of hexazine rings in potassium polynitride at high pressure [J]. Nature Chemistry, 2022, 14(7): 794–800. doi: 10.1038/s41557-022-00925-0
[17]	LI D M, WU X X, JIANG J R, et al. Pressure-induced phase transitions in rubidium azide: studied by in-situ X-ray diffraction [J]. Applied Physics Letters, 2014, 105(7): 071903. doi: 10.1063/1.4893464
[18]	LI D M, LI F F, LI Y, et al. High-pressure studies of rubidium azide by Raman and infrared spectroscopies [J]. The Journal of Physical Chemistry C, 2015, 119(29): 16870–16878. doi: 10.1021/acs.jpcc.5b05208
[19]	HOU D B, ZHANG F X, JI C, et al. Series of phase transitions in cesium azide under high pressure studied by in situ X-ray diffraction [J]. Physical Review B, 2011, 84(6): 064127. doi: 10.1103/PhysRevB.84.064127
[20]	LI D M, ZHU P F, JIANG J R, et al. High-pressure Raman and infrared spectroscopic studies of cesium azide [J]. The Journal of Physical Chemistry C, 2016, 120(47): 27013–27018. doi: 10.1021/acs.jpcc.6b09811
[21]	SUI M H, LIU S, WANG P, et al. High-pressure synthesis of fully sp²-hybridized polymeric nitrogen layer in potassium supernitride [J]. Science Bulletin, 2023, 68(14): 1505–1513. doi: 10.1016/j.scib.2023.06.029
[22]	ZHANG M G, YAN H Y, WEI Q, et al. Novel high-pressure phase with pseudo-benzene “N₆” molecule of LiN₃ [J]. Europhysics Letters, 2013, 101(2): 26004. doi: 10.1209/0295-5075/101/26004
[23]	WANG X L, LI J F, BOTANA J, et al. Polymerization of nitrogen in lithium azide [J]. The Journal of Chemical Physics, 2013, 139(16): 164710. doi: 10.1063/1.4826636
[24]	ZHANG M G, YIN K T, ZHANG X X, et al. Structural and electronic properties of sodium azide at high pressure: a first principles study [J]. Solid State Communications, 2013, 161: 13–18. doi: 10.1016/j.ssc.2013.01.032
[25]	ZHANG M G, YAN H Y, WEI Q, et al. A new high-pressure polymeric nitrogen phase in potassium azide [J]. RSC Advances, 2015, 5(16): 11825–11830. doi: 10.1039/C4RA15699D
[26]	ZHANG X W, ZUNGER A, TRIMARCHI G. Structure prediction and targeted synthesis: a new Na_nN₂ diazenide crystalline structure [J]. The Journal of Chemical Physics, 2010, 133(19): 194504. doi: 10.1063/1.3488440
[27]	SCHNEIDER S B, FRANKOVSKY R, SCHNICK W. High-pressure synthesis and characterization of the alkali diazenide Li₂N₂ [J]. Angewandte Chemie International Edition, 2012, 51(8): 1873–1875. doi: 10.1002/anie.201108252
[28]	SHEN Y Q, OGANOV A R, QIAN G R, et al. Novel lithium-nitrogen compounds at ambient and high pressures [J]. Scientific Reports, 2015, 5: 14204. doi: 10.1038/srep14204
[29]	ZHANG J, WANG X L, YANG K S, et al. The polymerization of nitrogen in Li₂N₂ at high pressures [J]. Scientific Reports, 2018, 8(1): 13144. doi: 10.1038/s41598-018-31355-z
[30]	WANG Y C, LV J, ZHU L, et al. Crystal structure prediction via particle-swarm optimization [J]. Physical Review B, 2010, 82(9): 094116. doi: 10.1103/PhysRevB.82.094116
[31]	WANG Y C, LV J, ZHU L, et al. CALYPSO: a method for crystal structure prediction [J]. Computer Physics Communications, 2012, 183(10): 2063–2070. doi: 10.1016/j.cpc.2012.05.008
[32]	LI Y W, FENG X L, LIU H Y, et al. Route to high energy density polymeric nitrogen t-N via He-N compounds [J]. Nature Communications, 2018, 9(1): 722. doi: 10.1038/s41467-018-03200-4
[33]	MA L, WANG K, XIE Y, et al. High-temperature superconducting phase in clathrate calcium hydride CaH₆ up to 215 K at a pressure of 172 GPa [J]. Physical Review Letters, 2022, 128(16): 167001. doi: 10.1103/PhysRevLett.128.167001
[34]	DUAN Q Z, SHEN J Y, ZHONG X, et al. Structural phase transition and superconductivity of ytterbium under high pressure [J]. Physical Review B, 2022, 105(21): 214503. doi: 10.1103/PhysRevB.105.214503
[35]	SUN W G, CHEN B L, LI X F, et al. Ternary Na-P-H superconductor under high pressure [J]. Physical Review B, 2023, 107(21): 214511. doi: 10.1103/PhysRevB.107.214511
[36]	KRESSE G, FURTHMÜLLER J. Efficient iterative schemes for ab initio total-energy calculations using a plane-wave basis set [J]. Physical Review B, 1996, 54(16): 11169–11186. doi: 10.1103/PhysRevB.54.11169
[37]	PERDEW J P, BURKE K, ERNZERHOF M. Generalized gradient approximation made simple [J]. Physical Review Letters, 1996, 77(18): 3865–3868. doi: 10.1103/PhysRevLett.77.3865
[38]	BLÖCHL P E. Projector augmented-wave method [J]. Physical Review B, 1994, 50(24): 17953–17979. doi: 10.1103/PhysRevB.50.17953
[39]	GRIMME S, ANTONY J, EHRLICH S, et al. A consistent and accurate ab initio parametrization of density functional dispersion correction (DFT-D) for the 94 elements H-Pu [J]. The Journal of Chemical Physics, 2010, 132(15): 154104. doi: 10.1063/1.3382344
[40]	MONKHORST H J, PACK J D. Special points for Brillouin-zone integrations [J]. Physical Review B, 1976, 13(12): 5188–5192. doi: 10.1103/PhysRevB.13.5188
[41]	TOGO A, TANAKA I. First principles phonon calculations in materials science [J]. Scripta Materialia, 2015, 108: 1–5. doi: 10.1016/j.scriptamat.2015.07.021
[42]	GATTI C. Chemical bonding in crystals: new directions [J]. Zeitschrift für Kristallographie-Crystalline Materials, 2005, 220(5/6): 399–457.
[43]	PENG F, HAN Y X, LIU H Y, et al. Exotic stable cesium polynitrides at high pressure [J]. Scientific reports, 2015, 5(1): 16902. doi: 10.1038/srep16902
[44]	BRILL T B, JAMES K J. Kinetics and mechanisms of thermal decomposition of nitroaromatic explosives [J]. Chemical Reviews, 1993, 93(8): 2667–2692. doi: 10.1021/cr00024a005
[45]	ZHANG S T, ZHAO Z Y, LIU L L, et al. Pressure-induced stable BeN₄ as a high-energy density material [J]. Journal of Power Sources, 2017, 365: 155–161. doi: 10.1016/j.jpowsour.2017.08.086
[46]	ZHAI H, XU R, DAI J H, et al. Stabilized nitrogen framework anions in the Ga-N system [J]. Journal of the American Chemical Society, 2022, 144(47): 21640–21647. doi: 10.1021/jacs.2c09056