Density Functional Calculations of Metal Clusters: Structure, Dynamics, and Reactivity - Metallic Systems: A Quantum Chemist's Perspective - page 294

4000

T
< T >

3500

3000

2500

2000

1500

1000

500

0

5 1005 2005 3005 4005

Time (fs)

5005 6005 7005

(a)

30

20

10

0

-10

-20

-30

4 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8

(b) q

FIGURE 9.7 Temperature. proile. (a). and. phase. space. distribution. (b). for. a. copper. dimer.
using.the.Nosé-Hoover.chain.thermostat.for.the.BOMD.simulation.

where.only.the.irst.thermostat.interacts.directly.with.the.real.system..This.method.
increases. the. ergodic. behavior. of. the. system. and,. therefore,. leads. to. the. cor-
rect. canonical. distribution. in. phase. space. as. the. BOMD. copper. dimer. simulation.
in. Figure. 9.7. shows.. Furthermore,. the. instantaneous. temperature. luctuations. are.
occurring.during.the.full.simulation.
These.four.schemes.are.implemented.in.the.most.recent.version.of.deMon2k..For.
the.calculation.of.temperature-dependent.molecular.properties,.we.have.made.good.
experiences.with.the.Nosé-Hoover.chain.thermostat.[39].

9.3 GEOMETRY OPTIMIZATION

9.3.1 f ree m etal c luSterS (v 3 , c u , n i )
Over. the. last. years,. the. knowledge. about. free. transition-metal. (TM). clusters.
has. grown. considerably,. due. to. many. reasons. such. as. the. development. of. novel.