Journal of Chemical Theory and Computation,
Год журнала:
2024,
Номер
20(10), С. 4146 - 4160
Опубликована: Май 9, 2024
Quantum
computing
is
emerging
as
a
new
computational
paradigm
with
the
potential
to
transform
several
research
fields
including
quantum
chemistry.
However,
current
hardware
limitations
(including
limited
coherence
times,
gate
infidelities,
and
connectivity)
hamper
implementation
of
most
algorithms
call
for
more
noise-resilient
solutions.
We
propose
an
explicitly
correlated
Ansatz
based
on
transcorrelated
(TC)
approach
target
these
major
roadblocks
directly.
This
method
transfers,
without
any
approximation,
correlations
from
wave
function
directly
into
Hamiltonian,
thus
reducing
resources
needed
achieve
accurate
results
noisy
devices.
show
that
TC
allows
shallower
circuits
improves
convergence
toward
complete
basis
set
limit,
providing
energies
within
chemical
accuracy
experiment
smaller
sets
and,
thus,
fewer
qubits.
demonstrate
our
by
bond
lengths,
dissociation
energies,
vibrational
frequencies
close
experimental
hydrogen
dimer
lithium
hydride
using
two
four
qubits,
respectively.
To
approach's
near-term
potential,
we
perform
experiments,
where
confirm
paves
way
chemistry
calculations
already
today's
hardware.
The Journal of Chemical Physics,
Год журнала:
2024,
Номер
160(22)
Опубликована: Июнь 10, 2024
The
software
for
chemical
interaction
networks
(SCINE)
project
aims
at
pushing
the
frontier
of
quantum
calculations
on
molecular
structures
to
a
new
level.
While
individual
as
well
simple
relations
between
them
have
become
routine
in
chemistry,
developments
pushed
field
high-throughput
calculations.
Chemical
may
be
created
by
search
specific
properties
design
attempt,
or
they
can
defined
set
elementary
reaction
steps
that
form
network.
modules
SCINE
been
designed
facilitate
such
studies.
features
are
(i)
general
applicability
applied
methodologies
ranging
from
electronic
structure
(no
restriction
elements
periodic
table)
microkinetic
modeling
(with
little
restrictions
molecularity),
full
modularity
so
also
stand-alone
programs
exchanged
external
packages
fulfill
similar
purpose
(to
increase
options
computational
campaigns
and
provide
alternatives
case
tasks
hard
impossible
accomplish
with
certain
programs),
(ii)
high
stability
autonomous
operations
control
steering
an
operator
easy
possible,
(iii)
embedding
into
complex
heterogeneous
environments
taken
individually
context
A
graphical
user
interface
unites
all
ensures
interoperability.
All
components
made
available
open
source
free
charge.
The Journal of Chemical Physics,
Год журнала:
2024,
Номер
161(6)
Опубликована: Авг. 12, 2024
Forte
is
an
open-source
library
specialized
in
multireference
electronic
structure
theories
for
molecular
systems
and
the
rapid
prototyping
of
new
methods.
This
paper
gives
overview
capabilities
Forte,
its
software
architecture,
examples
applications
enabled
by
methods
it
implements.
Journal of Chemical Theory and Computation,
Год журнала:
2024,
Номер
20(5), С. 1988 - 2009
Опубликована: Фев. 21, 2024
The
implementation
of
multireference
configuration
interaction
(MRCI)
methods
in
quantum
systems
with
large
active
spaces
is
hindered
by
the
expansion
bases
or
intricate
handling
reduced
density
matrices
(RDMs).
In
this
work,
we
present
a
spin-adapted
renormalized-residue-based
MRCI
(RR-MRCI)
approach
that
leverages
renormalized
residues
to
effectively
capture
entanglement
between
and
inactive
orbitals.
This
reinforced
novel
efficient
algorithm,
which
also
facilitates
an
deployment
matrix
product
state
(MPS-MRCI).
RR-MRCI
framework
possesses
several
advantages:
(1)
It
considers
orbital
utilizes
highly
compressed
MPS
structure,
improving
computational
accuracy
efficiency
compared
internally
contracted
(ic)
MRCI.
(2)
Utilizing
small-sized
buffer
environments
few
external
orbitals
as
probes
based
on
information
theory,
it
enhances
over
MPS-MRCI
offers
potential
application
molecular
systems.
(3)
RR
can
be
implemented
conjunction
ic-MRCI,
eliminating
need
for
high-rank
RDMs,
using
distinct
residues.
We
evaluated
method
across
nine
diverse
systems,
including
Cu
The Journal of Chemical Physics,
Год журнала:
2024,
Номер
160(20)
Опубликована: Май 28, 2024
Using
the
recently
developed
multistate
mapping
approach
to
surface
hopping
(multistate
MASH)
method
combined
with
SA(3)-CASSCF(12,12)/aug-cc-pVDZ
electronic
structure
calculations,
gas-phase
isotropic
ultrafast
electron
diffraction
(UED)
of
cyclobutanone
is
predicted
and
analyzed.
After
excitation
into
n-3s
Rydberg
state
(S2),
can
relax
through
two
S2/S1
conical
intersections,
one
characterized
by
compression
CO
bond
other
dissociation
α-CC
bond.
Subsequent
transfer
ground
(S0)
then
achieved
via
additional
S1/S0
intersections
that
lead
three
reaction
pathways:
α
ring-opening,
ethene/ketene
production,
liberation.
The
UED
signal
from
MASH
simulations,
allowing
for
a
direct
comparison
experimental
data.
This
work,
which
contribution
prediction
challenge,
facilitates
identification
main
photoproducts
in
thereby
emphasizes
importance
dynamics
simulations
interpretation
experiments.
Open-shell
systems
with
extensive
π-conjugation
have
fascinating
properties
due
to
their
narrow
bandgaps
and
spin
interactions.
In
this
work,
we
report
neutral
open-shell
di-
polyradical
conjugated
materials
exhibiting
intriguing
optical
magnetic
properties.
Our
key
design
advance
is
the
planarized
geometry
allowing
for
greater
interaction
between
adjacent
spins.
This
results
in
absorption
emission
near
infrared
at
803
1050
nanometers,
respectively,
demonstrate
a
unique
electronic
structure
where
bright
zwitterionic
excited
state
lowest-accessible
transition.
Electron
paramagnetic
resonance
spectroscopy
superconducting
quantum
interference
device
measurements
reveal
that
our
are
singlets
different
degrees
of
interactions,
dynamics,
antiferromagnetic
properties,
which
likely
contributed
formation
emissive
singlet
near-infrared
emission.
addition,
show
reversible
stable
electrochromic
switching
more
than
500
cycles,
indicating
potential
optoelectronic
electrochemical
energy
storage
applications.
Journal of Computational Chemistry,
Год журнала:
2025,
Номер
46(2)
Опубликована: Янв. 11, 2025
ABSTRACT
Light‐driven
molecular
rotary
motors
are
nanometric
machines
able
to
convert
light
into
unidirectional
motions.
Several
types
of
have
been
developed
better
respond
stimuli,
opening
new
avenues
for
developing
smart
materials
ranging
from
nanomedicine
robotics.
They
great
importance
in
the
scientific
research
across
various
disciplines,
but
a
detailed
comprehension
underlying
ultrafast
photophysics
immediately
after
photo‐excitation,
that
is,
Franck–Condon
region
characterization,
is
not
fully
achieved
yet.
For
this
aim,
it
first
required
rely
on
an
accurate
description
at
ab
initio
level
system
potential
energy
before
performing
any
further
step,
dynamics.
Thus,
we
present
extensive
investigation
aimed
accurately
describing
electronic
structure
low‐lying
states
(electronic
layout)
rotor
region,
belonging
class
overcrowded
alkenes:
9‐(2‐methyl‐2,3‐dihydro‐1H‐cyclopenta[a]naphthalen‐1‐ylidene)‐9H‐fluorene.
This
was
chosen
since
its
very
interesting
more
general
understanding
similar
compounds
used
as
rotors,
where
can
be
found
(whose
energetic
interplay
crucial
dynamics)
and
presence
different
substituents
tune
HOMO‐LUMO
gap.
scope,
employed
theory
levels
within
time‐dependent
density
functional
framework,
presenting
also
careful
comparison
adopting
post
Hartree–Fock
methods
characterizing
conformations
involved
photocycle.
Effects
layout
functionals,
basis
sets,
environment
descriptions,
role
dispersion
correction
were
all
analyzed
detail.
In
particular,
treatment
solvent
effects
here
considered
depth,
showing
how
implicit
excited
by
testing
both
linear‐response
state‐specific
formalisms.
As
main
results,
chose
two
cost‐effective
(accurate
relatively
cheap)
ground
state
verified
choosing
these
influence
curvature
via
frequency
analysis
normal
modes
vibrations
active
Raman
spectrum.
theoretical
survey
step
towards
feasible
characterization
early
stage
solution
during
photoisomerization
processes
wherein
multiple
might
populated
upon
radiation,
leading
future
molecular‐level
interpretation
time‐resolved
spectroscopies.
Journal of Chemical Theory and Computation,
Год журнала:
2025,
Номер
unknown
Опубликована: Янв. 24, 2025
Determining
the
energetics
of
triplet
electronic
states
nucleobases
in
biological
macromolecular
environment
nucleic
acids
is
essential
for
an
accurate
description
mechanism
photosensitization
and
design
drugs
cancer
treatment.
In
this
work,
we
aim
at
developing
a
methodological
approach
to
obtain
free
energies
triplets
DNA
beyond
state
art,
able
reproduce
decrease
measured
experimentally
T
(270
kJ/mol)
vs
isolated
nucleotide
aqueous
solution
(310
kJ/mol).
For
such
purposes,
adapt
energy
perturbation
method
compute
related
transformation
pure
singlet
into
via
"alchemical"
intermediates
with
mixed
singlet–triplet
nature.
By
means,
standard
deviation
errors
are
only
few
kJ/mol,
contrary
large
tenths
kJ/mol
obtained
by
averaging
derived
from
molecular
dynamics
simulations.
The
reduced
statistical
allow
us
rationalize
confidence
stabilization
observed
when
comparing
thymine
DNA.
Spin
polarization
rather
than
excimer
interactions
between
π-stacked
originates
lower
values
developed
implemented
QM3
shall
be
useful
determining
other
like
ionic
or
charge
separation
any
system
impact
biomedicine
materials
science.
The Journal of Physical Chemistry A,
Год журнала:
2025,
Номер
unknown
Опубликована: Янв. 26, 2025
The
energy
gaps,
spin-orbit
coupling
(SOC),
and
admixture
coefficients
over
a
series
of
the
configurations
are
evaluated
by
SA-CASSCF/6-31G,
SA-CASSCF/6-31G*,
SA-CASSCF/ANO-RCC-VDZP,
MS-CASPT2/ANO-RCC-VDZP
to
reveal
extent
inaccuracy
SA-CASSCF.
By
comparing
mean
absolute
errors
for
gaps
coefficient
magnitudes
(ACMs)
measured
between
or
SA-CASSCF/ANO-RCC-VDZP
MS-CASPT2/ANO-RCC-VDZP,
SA-CASSCF/6-31G
is
selected
as
electronic
structure
method
in
nonadiabatic
molecular
dynamics
simulation.
major
components
ACMs
identified
compared;
we
find
that
underestimated
which
verified
reasonable
triplet
quantum
yield
simulated
trajectory
surface
hopping
calibrated
SA-CASSCF/6-31G.
magnitude
singlet-triplet
mixing
positively
correlates
probability
mixed
singlet
states,
confirmed
computed
S-T
transition
probability.
JACS Au,
Год журнала:
2025,
Номер
5(3), С. 1196 - 1212
Опубликована: Фев. 21, 2025
Lanthanide
(Ln)
magnetic
resonance
imaging
and
chiral
shift
reagents
generally
exploit
1H
NMR
shifts,
as
paramagnetic
broadening
tends
to
preclude
the
use
of
heavier,
less
sensitive
nuclei.
Here,
we
report
solution
solid-state
31P
shifts
an
isostructural
series
distorted
trigonal
bipyramidal
Ln(III)
tris-silylphosphide
complexes,
[Ln{P(SiMe3)2}3(THF)2]
(1-Ln;
Ln
=
La,
Ce,
Pr,
Nd,
Sm);
1-Ln
was
also
characterized
by
elemental
analysis;
single-crystal
powder
X-ray
diffraction;
multinuclear
NMR,
EPR,
ATR-IR,
UV–vis-NIR
spectroscopy;
SQUID
magnetometry.
Breaking
assumptions,
observed
paramagnetically
broadened
spectra
for
Ln-bound
P
atoms
family;
in
solution,
1-Nd
showed
most
downfield
chemical
(δ{31P}
2570.14
ppm)
1-Sm
upfield
value
−259.21
ppm).
We
determined
span
anisotropies
(CSAs)
solid
using
magic
angle
spinning
CSA
largest
1-Pr
(Ω{31P}
≈
2000
ppm),
consistent
with
a
combination
paramagnetism
relatively
large
differences
pyramidalization
three
solid-state.
Density
functional
theory
calculations
1-La
were
excellent
agreement
experimentally
parameters.
find
good
experimental
ab
initio-calculated
values
1-Ln,
while
heavier
13C,
29Si,
nuclei
are
not
well-reproduced
due
current
limitations
contact
shifts.