%0 DATA
%A Omar, López-Estrada
%A Emilio, Orgaz
%D 2015
%T Theoretical Study of the Spin Competition in Small-Sized Al Clusters
%U https://acs.figshare.com/articles/Theoretical_Study_of_the_Spin_Competition_in_Small_Sized_Al_Clusters/2100568
%R 10.1021/acs.jpca.5b09871.s001
%2 https://acs.figshare.com/ndownloader/files/3733834
%K MP
%K Al 8 clusters
%K ground state
%K Spin Competition
%K 0 K ground
%K simulation temperatures
%K CCSD
%K 0 K
%K Al clusters exhibit
%K deflection signal
%K Theoretical Study
%K dynamics results
%K electron correlation
%K singlet
%K Al 6
%K aluminum clusters
%K density functionals
%K SG
%K DFT computations
%K structure investigations show ambiguity
%X Stern–Gerlach
(SG) experiments on aluminum clusters indicate that some small-sized
aggregates exhibit a deflection signal consistent with the existence
of magnetic moments. However, in the particular case of Al_{6} and Al_{8} clusters, electronic structure investigations
show ambiguity on the 0 K ground spin state. In this work extensive
computations of the electronic structure have been carried out in
order to determine the ground state of these structures. Electron
correlation has been introduced at MP2, MP4, and CCSD(T) theory level
as well as by DFT computations with different density functionals.
DFT-based Born–Oppenheimer molecular dynamics results at different
simulation temperatures complete this investigation. One of our main
conclusions is that singlet spin states are systematically the more
stable configuration at 0 K. These Al clusters exhibit almost degenerate
electronic structures at singlet and triplet spin states. The geometries
are similar, and the paths connecting both structures allow an intersystem
crossing through a spin–orbit coupling mechanism, indicating
a dynamical interchange of both spin states at finite temperatures.