第
30
卷第
6
期
Vol.30
,
No.6
西华大学学报(自然科学版)
Joumal
of
Xihua
University •
Natural
Science
2011
年
11
月
Nov.2011
文章编号:
1673-159X(2011 )06
-0
069
-0
4
AU
n
Cd
(n
= 1 - 8
)团簇的结构和稳定性
郭建军
1
,郭思琪
2
,杨继先
1
(1.西华大学物理与化学学院,四川成都
610039:2
西华大学机械工程与自动化学院,四川成都
610039)
摘
要:系统研究了二元合金团簇
AU
n
Cd
(n
= 1 - 8
)的结构和最低能量异构体的相对稳定性,结果表明:
AuπCd(n=1-8)
团簇的基态几何结构为平面结构,奇数个原子的团簇比偶数个原子团簇的稳定性高,
Au
2
Cd
为幻
数团簇,具有较高的稳定性。
关键词:密度泛函理论
;Au-Cd
团簇;结构;稳定性
中图分类号
:0562
文献标志码
:A
Geometry
and
Stability of
Cd@
AU
n
(n
= 1 -
8)
Clusters
GUO
Jian-Jun
1
,
GUO
Shi-qi
2
,
YANG
Ji-xian
1
(
1.
School
of
Physics and Chemistry , Xihua University , Chengdu 610039 China;
2.
School
of
Mechanical Engineering and Automation, Xihua University , Chengdu 610039 China)
Abstract:
The
geometrical configuration and relative stability
of
the lowest-lying isomers
of
cadmium-doped
gold
clusters ,
AU
n
Cd
( n = 1 -
8)
are investigated.
The
results obtained indicate that the
lowest
energy structure
of
AU
n
Cd
(n
= 1 -
8)
clusters
is
plana
r.
The stability trend
of
the
Au"
Cd
cluster
shows
an
odd-even oscillation
with
the even numbered clusters
is
more
stable ,
and
indicates
that
AU
2
Cd
cluster
is
magic
one
with
high
chemical stability.
Key words: density functional theory; Au-Cd cluster; structure; stability
1 INTRODUCTION
Recently
,
the
noble-metal
(Cu
, Ag ,
and
Au)
clusters
have
been
aroused
considerable
interests
by
chemists
and
physicists
due
to
their
unique
physical
and
chemical
properties
[1
-13
J. F
or
example
,
the
geo-
metric
structures
,
relative
stabilities ,
and
magnetic
moments
of
the
small
AunFe
(n
=
1
一
7)
clusters
have
been
investigated
systematically
by
density
functional
theo
巧
(DFT)
in
Re
f.
[2].
Nonlinear
optical
proper-
ties
of
Aun_mMm(M=Ag
,
Cu;
m=l
,
2)
clusters
are
theoretically
investigated
by
Xu
et
α
1.
[3
J.
Bouwen
et
α
l.
[6J
investigated
the
bimetallic
A
飞
X;(X=Cu
,
AI ,
Y ,
In)
clusters.
Koyasu
et
α
1.
[7J
investigated
AunPd
-
(n
= 1 -
4)
cluster
anions
using
anion
photoelectron
spectroscopy.
Yuan
et
al.
[8J
investigated
the
geomet-
ric
,
electronic
,
and
bonding
properties
of
AuNM
(N
=
1
-7
, M =
Ni
,时,
Pt)
clusters.
In
this
paper
,
the
geometric configurations
and
stability
trend
of
Au
工
d
(n
= 1 -
8)
clusters
were
sys-
tematically
investigated
using
the
density
functional
Received
date
:2011
-D
9-20
method
PW91
P86
with relativistic effective
core
poten-
tials
(RECP)
and
LAN12DZ
basis
set
as
used
in
the
A
飞
Zn
(n
= 1 -
8)
cluster
optimizations
[川.
2 RESUL TS AND DISCUSSION
2.
1
The
lowest
energy
structure
and
vibrational
property
The
results
show
that
the
ground
state
of
AuCd
is
doublet
spin
state
as
it
also
occurs
in
the
AuZn
cluster
optimizations
[川.
The
calculated
bond
length
(2.
68
λ)
and
vibrational
frequency
(141
cm
-1)
are
in
good
agreement
with
previous
theoretical
bond
length
(2.
69
Å)
and
vibrational
frequency
(138
cm
-1
)
[4]
.
Many isomers
have
been
obtained
in
the
AU
n
Cd
(n
= 2 -
8)
clusters
optimizations.
Figure
1 shows
the
most
stable
structure
and
the
low-Iying
isomers
for
each
A
飞
Cd
(n
= 2 -
8)
cluste
r.
It
is
obvious
that
the
ground-state
structures
of
AU
n
Cd
(n
= 1 -
8)
clus-
ters
favor
the
planar
structures.
The
lowest
energy
structure
of
AU
2
Cd
is
the
linear
structure
with
central
Cd
atom
as
it also
occurred
in
the
Au
2
Zn
cluster
opti-
Biography:
Guo
Jian-jun
(
1964-)
,
Male
,
Professor
,
Master
,
His
Research
lnterests
lnclude
Atomic
and
Molecular
Physics.