%0 Journal Article
%A Brea, Oriana
%A Khatib, Muammar El
%A Bendazzoli, Gian Luigi
%A Evangelisti, Stefano
%A Leininger, Thierry
%A Angeli, Celestino
%D 2016
%T The Spin-Partitioned Total-Position Spread Tensor:
An Application To Diatomic Molecules
%U https://acs.figshare.com/articles/journal_contribution/The_Spin_Partitioned_Total_Position_Spread_Tensor_An_Application_To_Diatomic_Molecules/3205087
%R 10.1021/acs.jpca.6b01043.s001
%2 https://acs.figshare.com/ndownloader/files/5030182
%K moment cumulant
%K SP
%K configuration interaction
%K molecule charge mobility
%K covalent bonds
%K tensor
%K Λ αα
%K Λ αβ
%K FCI
%K delocalization
%K TPS
%K energy curve
%K position operator
%K SS
%K partition
%K multireference character
%K wave function
%K Diatomic Molecules
%X The
spin partition (SP) of the total-position spread (TPS) tensor
is applied to the case of a few light diatomic molecules at full configuration
interaction (FCI) level. It appears that the SP-TPS tensor gives informations
that are complementary with respect to the corresponding spin-summed
(SS) quantity. The spin-summed total position-spread tensor (SS-TPS,
Λ) is defined as the second moment cumulant of the total position
operator, and the SP-TPS is its partition in equal (Λαα+ββ) and different spin (Λαβ+βα) contributions. Then, the
SS-TPS allows description of the molecule charge mobility, while the
SP-TPS allows description of the spin delocalization. The most relevant
Cartesian-component for both tensors (SS-TPS and SP-TPS) is the component
along the chemical bond (Λ∥), and it was found
that its behavior was related to the type of interaction involved.
For covalent bonds the SP-TPS has a squared growth when the bond is
stretched, while for ionic bonds there exists a faster-than-linear
growth after the avoided-crossing between the covalent and the ionic
states. Other exotic bonds, like He2 and Be2, were also considered, and a particular spin delocalization was
able to describe the different character of the two weakly bonded
molecules, and specially the multireference character of the wave
function along the dissociative potential energy curve.
%I ACS Publications