Machine-Learned Kohn–Sham Hamiltonian Mapping for Nonadiabatic Molecular Dynamics
Journal of Chemical Theory and Computation,
Journal Year:
2024,
Volume and Issue:
20(8), P. 2992 - 3007
Published: April 6, 2024
In
this
work,
we
report
a
simple,
efficient,
and
scalable
machine-learning
(ML)
approach
for
mapping
non-self-consistent
Kohn-Sham
Hamiltonians
constructed
with
one
kind
of
density
functional
to
the
nearly
self-consistent
another
functional.
This
is
designed
as
fast
surrogate
Hamiltonian
calculator
use
in
long
nonadiabatic
dynamics
simulations
large
atomistic
systems.
approach,
input
output
features
are
matrices
computed
from
different
levels
theory.
We
demonstrate
that
developed
ML-based
method
(1)
speeds
up
calculations
by
several
orders
magnitude,
(2)
conceptually
simpler
than
alternative
ML
approaches,
(3)
applicable
systems
sizes
can
be
used
arbitrary
functionals,
(4)
requires
modest
training
data,
learns
fast,
generates
molecular
orbitals
their
energies
accuracy
matching
conventional
calculations,
(5)
when
applied
simulation
excitation
energy
relaxation
yields
corresponding
time
scales
within
margin
error
calculations.
Using
explore
C
Language: Английский
Nonadiabatic Dynamics with Exact Factorization: Implementation and Assessment
Journal of Chemical Theory and Computation,
Journal Year:
2024,
Volume and Issue:
20(12), P. 5022 - 5042
Published: June 5, 2024
In
this
work,
we
report
our
implementation
of
several
independent-trajectory
mixed-quantum-classical
(ITMQC)
nonadiabatic
dynamics
methods
based
on
exact
factorization
(XF)
in
the
Libra
package
for
and
excited-state
dynamics.
Namely,
surface
hopping
(SHXF),
mixed
quantum-classical
(MQCXF),
mean-field
(MFXF)
are
introduced.
Performance
these
is
compared
to
that
traditional
schemes,
such
as
fewest-switches
(FSSH),
branching-corrected
(BCSH),
simplified
decay
mixing
(SDM),
well
conventional
Ehrenfest
(mean-field,
MF)
method.
Based
a
comprehensive
set
1D
model
Hamiltonians,
find
ranking
SHXF
≈
MQCXF
>
BCSH
SDM
FSSH
≫
MF,
with
sometimes
outperforming
XF
terms
describing
coherences.
Although
MFXF
method
can
yield
reasonable
populations
coherences
some
cases,
it
does
not
conserve
total
energy
therefore
recommended.
We
also
branching
correction
auxiliary
trajectories
important
accurate
However,
worsen
quality
conservation
MQCXF.
Finally,
using
time-dependent
Gaussian
width
approximation
used
computing
decoherence
improve
The
parameter-free
scheme
Subotnik
widths
found
deliver
best
performance
situations
where
known
priori.
Language: Английский
Energy Transfer Mechanisms in Large Low-Bandgap Polymers from Time-Resolved Experiments and Nonadiabatic Molecular Dynamics Calculations
Chemistry of Materials,
Journal Year:
2025,
Volume and Issue:
37(10), P. 3769 - 3775
Published: May 14, 2025
Conjugated
polymers
offer
unprecedented
chemical
tunability
for
modulating
energy
transfer
in
a
multitude
of
infrared
light
applications.
In
this
work,
we
use
combination
time-resolved
spectroscopic
experiments
and
nonadiabatic
molecular
dynamics
calculations
to
probe
the
photochemistry
nonradiative
transitions
recently
synthesized
narrow
bandgap
donor-acceptor
conjugated
polymer
based
on
alternating
cyclopentadithiophene
electronegative
benzothiadiazole
heterocycles.
Using
large-scale
semi-empirical
dynamics,
which
can
treat
large
260-atom
hexamer,
calculate
an
S5
→
S1
lifetime
34.75
fs,
is
consistent
with
our
data.
Our
simulations
suggest
that
vibronic
motions
central
carbons
functional
groups
are
predominantly
involved
transitions,
excitation
becomes
more
localized
monomer
fragment
over
time.
The
combined
work
provides
mechanistic
insight
into
functionalities
be
tuned
enhance
other
prospective
low-bandgap
materials.
Language: Английский