Modeling ionic mobilities by scattering on electronic density isosurfaces: Application to silicon cluster anions

被引:139
作者
Shvartsburg, AA
Liu, B
Jarrold, MF
Ho, KM
机构
[1] Northwestern Univ, Dept Chem, Evanston, IL 60208 USA
[2] Iowa State Univ, Ames Lab, Ames, IA 50011 USA
[3] Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA
关键词
D O I
10.1063/1.481042
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
We have developed a new formalism to evaluate the gas-phase mobility of an ion based on elastic scattering on an electronic density isosurface (SEDI). In this method, the ion is represented by a surface of arbitrary shape defined as a set of points in space where the total electron density assumes a certain value. This value is the only adjustable parameter in the model. Conceptually, this treatment emulates the interaction between a drifting ion and the buffer gas atoms closer than the previously described methods, the exact hard spheres scattering (EHSS) model and trajectory calculations, where the scattering occurs in potentials centered on the nuclei. We have employed EHSS, trajectory calculations, and SEDI to compute the room temperature mobilities for low-energy isomers of Si-n (n less than or equal to 20) cations and anions optimized by density functional theory (DFT) in the local density approximation and generalized gradient approximation. The results produced by SEDI are in excellent agreement with the measurements for both charge states, while other methods can fit the mobilities for cations only. Using SEDI, we have confirmed the structural differences between Si-n(+) and Si-n(-) predicted by DFT calculations, including the major rearrangements for n = 9, 15, 16, and 18. We have also assigned the multiple isomers observed in recent high-resolution mobility measurements for Si-n(+) with n = 17-19, some of them to near-spherical cage-like geometries. (C) 2000 American Institute of Physics. [S0021-9606(00)01104-1].
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页码:4517 / 4526
页数:10
相关论文
共 90 条
[1]   STUDY OF SI4 AND SI4- USING THRESHOLD PHOTODETACHMENT (ZEKE) SPECTROSCOPY [J].
ARNOLD, CC ;
NEUMARK, DM .
JOURNAL OF CHEMICAL PHYSICS, 1993, 99 (05) :3353-3362
[2]   THRESHOLD PHOTODETACHMENT ZERO-ELECTRON KINETIC-ENERGY SPECTROSCOPY OF SI-3(-) [J].
ARNOLD, CC ;
NEUMARK, DM .
JOURNAL OF CHEMICAL PHYSICS, 1994, 100 (03) :1797-1804
[3]   PHOTOEMISSION SPECTRA AND STRUCTURES OF SI CLUSTERS AT FINITE-TEMPERATURE [J].
BINGGELI, N ;
CHELIKOWSKY, JR .
PHYSICAL REVIEW LETTERS, 1995, 75 (03) :493-496
[4]   UNIFIED APPROACH FOR MOLECULAR-DYNAMICS AND DENSITY-FUNCTIONAL THEORY [J].
CAR, R ;
PARRINELLO, M .
PHYSICAL REVIEW LETTERS, 1985, 55 (22) :2471-2474
[5]   CHEMICAL-REACTIVITY AND COVALENT-METALLIC BONDING OF SIN + (N= 11-25) CLUSTERS [J].
CHELIKOWSKY, JR ;
PHILLIPS, JC .
PHYSICAL REVIEW LETTERS, 1989, 63 (15) :1653-1656
[6]   Atomic and electronic structure of silicon clusters at finite temperature [J].
Chelikowsky, JR ;
Binggeli, N .
CLUSTER ASSEMBLED MATERIALS, 1996, 232 :87-102
[7]   SURFACE AND THERMODYNAMIC INTERATOMIC FORCE-FIELDS FOR SILICON CLUSTERS AND BULK PHASES [J].
CHELIKOWSKY, JR ;
PHILLIPS, JC .
PHYSICAL REVIEW B, 1990, 41 (09) :5735-5745
[8]   ULTRAVIOLET PHOTOELECTRON-SPECTROSCOPY OF SEMICONDUCTOR CLUSTERS - SILICON AND GERMANIUM [J].
CHESHNOVSKY, O ;
YANG, SH ;
PETTIETTE, CL ;
CRAYCRAFT, MJ ;
LIU, Y ;
SMALLEY, RE .
CHEMICAL PHYSICS LETTERS, 1987, 138 (2-3) :119-124
[9]   BINDING-ENERGIES AND ELECTRON-AFFINITIES OF SMALL SILICON CLUSTERS (N = 2-5) [J].
CURTISS, LA ;
DEUTSCH, PW ;
RAGHAVACHARI, K .
JOURNAL OF CHEMICAL PHYSICS, 1992, 96 (09) :6868-6872
[10]   Structural transitions and global minima of sodium chloride clusters [J].
Doye, JPK ;
Wales, DJ .
PHYSICAL REVIEW B, 1999, 59 (03) :2292-2300