The Journal of Chemical Physics,
Journal Year:
2024,
Volume and Issue:
161(22)
Published: Dec. 10, 2024
Water
confined
in
nanoscale
cavities
plays
a
crucial
role
everyday
phenomena
geology
and
biology,
as
well
technological
applications
at
the
water–energy
nexus.
However,
even
understanding
basic
properties
of
nano-confined
water
is
extremely
challenging
for
theory,
simulations,
experiments.
In
particular,
determining
melting
temperature
quasi-one-dimensional
ice
polymorphs
carbon
nanotubes
has
proven
to
be
an
exceptionally
difficult
task,
with
previous
experimental
classical
simulation
approaches
reporting
values
ranging
from
∼180
K
up
∼450
ambient
pressure.
this
work,
we
use
machine
learning
potential
that
delivers
first
principles
accuracy
(trained
density
functional
theory
approximation
revPBE0-D3)
study
phase
diagram
confinement
diameters
9.5
<
d
12.5
Å.
We
find
several
distinct
melt
surprisingly
narrow
range
between
∼280
∼310
K,
mechanism
depends
on
nanotube
diameter.
These
results
shed
new
light
one-dimension
have
implications
operating
conditions
carbon-based
filtration
desalination
devices.
Journal of Chemical Theory and Computation,
Journal Year:
2025,
Volume and Issue:
unknown
Published: Feb. 13, 2025
The
magnetite/water
interface
is
commonly
found
in
nature
and
plays
a
crucial
role
various
technological
applications.
However,
our
understanding
of
its
structural
dynamical
properties
at
the
molecular
scale
remains
still
limited.
In
this
study,
we
developed
an
efficient
Behler-Parrinello
neural
network
potential
(NNP)
for
system,
paying
particular
attention
to
accurate
generation
reference
data
with
density
functional
theory.
Using
NNP,
performed
extensive
dynamics
simulations
magnetite
(001)
surface
across
wide
range
water
coverages,
from
single
molecules
bulk
water.
Our
revealed
several
new
ground
states
low
coverage
on
Subsurface
Cation
Vacancy
(SCV)
model
yielded
profile
that
exhibits
marked
layering.
By
calculating
mean
square
displacements,
obtained
quantitative
information
diffusion
SCV
different
revealing
significant
anisotropy.
Additionally,
provided
qualitative
insights
into
dissociation
mechanisms
surface.
ACS Nano,
Journal Year:
2025,
Volume and Issue:
unknown
Published: April 28, 2025
Water's
ability
to
autoionize
into
hydroxide
and
hydronium
ions
profoundly
influences
surface
properties,
rendering
interfaces
either
basic
or
acidic.
While
it
is
well-established
that
protons
show
an
affinity
the
air-water
interface,
a
critical
knowledge
gap
exists
in
technologically
relevant
surfaces
like
graphene-water
interface.
Here
we
use
machine
learning-based
simulations
with
first-principles
accuracy
unravel
behavior
of
at
Our
findings
reveal
accumulate
ion
predominantly
residing
first
contact
layer
water.
In
contrast,
exhibits
bimodal
distribution,
found
both
near
further
away
from
it.
Analysis
underlying
electronic
structure
reveals
local
polarization
effects,
resulting
counterintuitive
charge
rearrangement.
Proton
propensity
interface
challenges
interpretation
experiments
expected
have
far-reaching
consequences
for
conductivity,
interfacial
reactivity,
proton-mediated
processes.
The Journal of Chemical Physics,
Journal Year:
2025,
Volume and Issue:
162(17)
Published: May 6, 2025
Machine
learning
potentials
(MLPs)
have
become
a
popular
tool
in
chemistry
and
materials
science
as
they
combine
the
accuracy
of
electronic
structure
calculations
with
high
computational
efficiency
analytic
potentials.
MLPs
are
particularly
useful
for
computationally
demanding
simulations
such
determination
free
energy
profiles
governing
chemical
reactions
solution,
but
to
date,
applications
still
rare.
In
this
work,
we
show
how
umbrella
sampling
can
be
combined
active
high-dimensional
neural
network
(HDNNPs)
construct
systematic
way.
For
example
first
step
Strecker
synthesis
glycine
aqueous
provide
detailed
analysis
improving
quality
HDNNPs
datasets
increasing
size.
We
find
that,
addition
typical
quantification
force
errors
respect
underlying
density
functional
theory
data,
long-term
stability
convergence
physical
properties
should
rigorously
monitored
obtain
reliable
converged
solution.
We
investigate
the
density
isobars
of
water
and
melting
temperature
ice
using
six
different
functionals.
Machine-learning
potentials
are
employed
to
ensure
computational
affordability.
Our
findings
reveal
significant
discrepancies
between
various
base
Notably,
even
choice
damping
can
result
in
substantial
differences.
Overall,
outcomes
obtained
through
functional
theory
not
entirely
satisfactory
across
most
utilized
All
functionals
exhibit
deviations
either
or
equilibrium
volume,
with
them
predicting
an
incorrect
volume
difference
water.
heuristic
analysis
indicates
that
a
hybrid
25%
exact
exchange
van
der
Waals
averaged
zero
Becke-Johnson
dampings
yields
closest
agreement
experimental
data.
This
study
underscores
necessity
for
further
enhancements
treatment
interactions
and,
more
broadly,
theory,
enable
accurate
quantitative
predictions
molecular
liquids.
Physical Review Materials,
Journal Year:
2024,
Volume and Issue:
8(7)
Published: July 18, 2024
The
diffusive
phase
transformations
occurring
in
feldspar,
a
common
mineral
the
crust
of
Earth,
are
essential
for
reconstructing
thermal
histories
magmatic
and
metamorphic
rocks.
Due
to
long
timescales
over
which
these
proceed,
mechanism
responsible
sodium
diffusion
its
possible
anisotropy
has
remained
topic
debate.
To
elucidate
this
defect-controlled
process,
we
have
developed
neural
network
potential
(NNP)
trained
on
first-principle
calculations
Na-feldspar
(albite)
charged
defects.
This
force
field
reproduces
various
experimentally
known
properties
including
lattice
parameters
elastic
constants
as
well
heat
capacity
DFT-calculated
defect
formation
energies.
A
new
type
dumbbell
interstitial
is
found
be
most
favorable,
free
energy
at
finite
temperature
calculated
using
thermodynamic
integration.
necessity
electrostatic
corrections
before
training
an
NNP
demonstrated
by
predicting
more
consistent
Published
American
Physical
Society
2024
The Journal of Chemical Physics,
Journal Year:
2024,
Volume and Issue:
161(8)
Published: Aug. 28, 2024
Biphasic
interfaces
are
complex
but
fascinating
regimes
that
display
a
number
of
properties
distinct
from
those
the
bulk.
The
CO2–H2O
interface,
in
particular,
has
been
subject
studies
on
account
its
importance
for
carbon
life
cycle
as
well
capture
and
sequestration
schemes.
Despite
this
attention,
there
remain
open
questions
nature
particularly
concerning
interfacial
tension
phase
behavior
CO2
at
interface.
In
paper,
we
seek
to
address
these
ambiguities
using
ab
initio-quality
simulations.
Harnessing
benefits
machine-learned
potentials
enhanced
statistical
sampling
methods,
present
an
initio-level
description
Interfacial
tensions
predicted
1
500
bars
found
be
close
agreement
with
experiment
pressures
which
experimental
data
available.
Structural
analyses
indicate
buildup
adsorbed,
saturated
film
forming
low
pressure
(20
bars)
similar
bulk
liquid,
preferential
perpendicular
alignment
respect
monolayer
coincides
reduced
structuring
water
molecules
This
study
highlights
predictive
macroscopic
biphasic
interfaces,
mechanistic
insight
obtained
into
dioxide
aggregation
interface
is
high
relevance
geoscience,
climate
research,
materials
science.
The Journal of Chemical Physics,
Journal Year:
2024,
Volume and Issue:
161(17)
Published: Nov. 1, 2024
Machine
learning
interatomic
potentials
(MLIPs)
provide
an
optimal
balance
between
accuracy
and
computational
efficiency
allow
studying
problems
that
are
hardly
solvable
by
traditional
methods.
For
metallic
alloys,
MLIPs
typically
developed
based
on
density
functional
theory
with
generalized
gradient
approximation
(GGA)
for
the
exchange-correlation
functional.
However,
recent
studies
have
shown
this
standard
protocol
can
be
inaccurate
calculating
transport
properties
or
phase
diagrams
of
some
alloys.
Thus,
optimization
choice
specific
calculation
parameters
is
needed.
In
study,
we
address
issue
Al-Cu
in
which
Perdew-Burke-Ernzerhof
(PBE)-based
cannot
accurately
calculate
viscosity
melting
temperatures
at
Cu-rich
compositions.
We
built
different
functionals,
including
meta-GGA,
using
a
transfer
strategy,
allows
us
to
reduce
amount
training
data
order
magnitude
compared
approach.
show
r2SCAN-
PBEsol-based
much
better
describing
thermodynamic
particular,
r2SCAN-based
deep
machine
potential
quantitatively
reproduce
concentration
dependence
dynamic
viscosity.
Our
findings
contribute
development
quantum
chemical
accuracy,
one
most
challenging
modern
materials
science.
The Journal of Chemical Physics,
Journal Year:
2024,
Volume and Issue:
161(20)
Published: Nov. 27, 2024
The
introduction
of
machine
learned
potentials
(MLPs)
has
greatly
expanded
the
space
available
for
studying
Nuclear
Quantum
Effects
computationally
with
ab
initio
path
integral
(PI)
accuracy,
MLPs'
promise
an
accuracy
comparable
to
that
at
a
fraction
cost.
One
challenges
in
development
MLPs
is
need
large
and
diverse
training
set
calculated
by
methods.
This
dataset
should
ideally
cover
entire
phase
space,
while
not
searching
this
using
methods,
as
would
be
counterproductive
generally
intractable
respect
computational
time.
In
paper,
we
present
self-learning
PI
hybrid
Monte
Carlo
Method
mixed
ML
potential
(SL-PIHMC-MIX),
where
allows
study
larger
systems
extension
original
SL-HMC
method
[Nagai
et
al.,
Phys.
Rev.
B
102,
041124
(2020)]
methods
systems.
While
generated
can
directly
applied
run
long-time
ML-PIMD
simulations,
demonstrate
PIHMC-MIX
trained
exact
reproduction
structure
obtained
from
PIMD.
Specifically,
find
simulations
require
only
5000
evaluations
32-bead
structure,
compared
100
000
needed
PIMD
result.