Density Functional Theory Calculations on Cobalt and Platinum Transition Metal Clusters - Metallic Systems: A Quantum Chemist's Perspective - page 361

Non-SO SO

2.585

2.668

2.651

2.590 2.668

2.585

2.668

2.590 2.586 2.651

2.590 2.587

2.540 2.549

2.578

2.597

2.547

2.540

2.548

2.540

2.540

2.548

2.487

2.492

2.492

2.487

2.487 2.492 2.492

2.487

2.476

2.417

2.584

2.565

2.592

2.584

2.455

2.469

FIGURE 10.6 Relaxed. geometries. of. Pt 4 . isomers. for. the. most. stable. spin. multiplicity.
of. each. isomer. with. and. without. SO. coupling. effects. (distances. are. in. Å ).. (PCCP. Owner.
Societies,.Sebetci,.A.,.Does.spin.orbit.coupling.effect.favour.planar.structures.for.small.plati-
num. clusters,. Phys. Chem. Chem. Phys .,. 11,. 921,. 2009.. Reproduced. by. permission. of. The.
Royal.Chemical.Society.)

as.the.lowest.energy.structure.for.the.non-SO.case.in.agreement.with.our.previous.
calculations.[39],.SO.coupling.effects.favor.a.pyramid.with.5.58.μ B .spin.moment..The.
energy. separation. between. the. capped. tetrahedron. and. the. pyramid. in. the. former.
case.is.only.11.meV,.which.may.be.considered.within.the.accuracy.of.the.calculations.
(remember.that.the.energy.convergence.criteria.is.chosen.as.about.0.03.meV)..On.the.
other.hand,.SO.coupling.effects.favor.the.pyramidal.structure.over.the.tetrahedral.
structure.by.as.much.as.167.meV..While.the.lowest.energy.structure.obtained.for.the.