Molecule–Environment Embedding with Quantum Monte Carlo: Electrons Interacting with Drude Oscillators
Journal of Chemical Theory and Computation,
Journal Year:
2025,
Volume and Issue:
unknown
Published: April 30, 2025
We
present
a
comprehensive
investigation
of
the
El-QDO
embedding
method
[Phys.
Rev.
Lett.
131,
228001
(2023)],
where
molecular
systems
described
through
electronic
Hamiltonian
are
immersed
in
bath
charged
quantum
harmonic
oscillators,
i.e.,
Drude
oscillators
(QDOs).
In
model,
entire
system
electrons
and
drudons─the
particles
QDOs─is
modeled
single
which
is
solved
Monte
Carlo
(QMC)
methods.
first
describe
details
Hamiltonian,
proposed
ansatz,
QMC
algorithms
implemented
to
integrate
both
drudonic
degrees
freedom.
Then
we
analyze
short-range
regularization
functions
for
interacting
potential
between
QDOs
order
accurately
treat
equilibrium
repulsive
regions,
resolving
overpolarization
error
that
occurs
environment.
After
benchmarking
various
(damping)
on
cases
argon
water
dimers,
applied
study
solvation
energies
benzene
verifying
accuracy
approach
compared
accurate
fully
ab
initio
calculations.
Furthermore,
comparison
interaction
with
components
Symmetry-Adapted
Perturbation
Theory
calculations,
illustrate
El-QDO's
explicit
many-body
treatment
electrostatic,
polarization,
dispersion
interactions
subsystem
Language: Английский
RISMiCal: A software package to perform fast RISM/3D‐RISM calculations
Journal of Computational Chemistry,
Journal Year:
2024,
Volume and Issue:
45(17), P. 1470 - 1482
Published: March 12, 2024
Abstract
Solvent
plays
an
essential
role
in
a
variety
of
chemical,
physical,
and
biological
processes
that
occur
the
solution
phase.
The
reference
interaction
site
model
(RISM)
its
three‐dimensional
extension
(3D‐RISM)
serve
as
powerful
computational
tools
for
modeling
solvation
effects
chemical
reactions,
functions,
structure
formations.
We
present
RISM
integrated
calculator
(RISMiCal)
program
package,
which
is
based
on
3D‐RISM
theories
with
fast
GPU
code.
RISMiCal
has
been
developed
RISM/3D‐RISM
interfaces
external
programs
such
Gaussian16,
GAMESS,
Tinker.
Fast
single‐
multi‐GPU
codes
written
CUDA
would
enhance
availability
these
hybrid
methods
because
they
require
performance
many
computationally
expensive
calculations.
expect
our
package
can
be
widely
applied
solvent.
available
at
https://rismical-dev.github.io
.
Language: Английский
Lagrangian of extended multiconfigurational self-consistent field second-order quasidegenerate perturbation theory combined with reference interaction site model self-consistent field constraint spatial electron density
The Journal of Chemical Physics,
Journal Year:
2024,
Volume and Issue:
160(11)
Published: March 19, 2024
Lagrangians
of
the
state-averaged
multiconfigurational
self-consistent
field
(SA-MCSCF)
and
multistate
extended
second-order
quasidegenerate
perturbation
theory
(MS-XMCQDPT2)
coupled
with
reference
interaction
site
model
constraint
spatial
electron
density
are
defined.
In
addition,
variational
equations
were
derived
to
calculate
excitation
energies
target
molecules
dissolved
in
various
solvents.
The
was
applied
a
phenol
molecule
solutions,
gradients
Hessian
matrices
calculated
evaluate
absorption
spectral
lines,
including
broadening
bandwidth.
Numerical
calculations
revealed
fine
structures
any
solvent
surroundings.
main
intramolecular
vibrational
modes
related
such
stretching
vibrations
aromatic
ring
oxygen
atom
molecule.
present
plays
an
important
role
predicting
structure
potential
energy
surfaces,
as
for
types,
during
photoexcitation
process.
Language: Английский
Vibrational Self-Consistent Field (VSCF) and Post-VSCF Method Calculations Combined with the Reference Interaction Site Model Self-Consistent Field Method Coupled with the Constrained Spatial Electron Density Distribution: Applications to NaHCOO in Aqueous Phase
Journal of Chemical Theory and Computation,
Journal Year:
2024,
Volume and Issue:
20(11), P. 4885 - 4892
Published: May 30, 2024
Investigating
vibrational
behavior
in
solution
is
crucial
for
understanding
molecular
dynamics
within
a
solvent
environment.
Notably,
the
analysis
of
Raman
spectra
molecules
important
owing
to
its
ability
unveil
intricate
solute–solvent
interactions.
Previous
studies
have
effectively
employed
frequency
calculations
utilizing
reference
interaction
site
model
self-consistent
field
method
conjunction
with
constrained
spatial
electron
density
distribution
(RISM–SCF–cSED)
understand
vibrations
solution,
primarily
focusing
on
fundamental
modes.
However,
oversight
overtones
and
combination
tones
these
prompted
us
combine
(VSCF)
second-order
Mo̷ller–Plesset
perturbation
(VMP2)
methods
RISM–SCF–cSED
address
aspects
theoretically.
Illustrating
efficacy
this
integrated
approach,
we
computed
sodium
formate
(NaHCOO)
water,
revealing
necessity
accounting
anharmonicity
analysis.
Our
findings
underscore
potency
VSCF
VMP2
as
robust
theoretical
framework
such
calculations.
Language: Английский
Spin–Spin Coupling Constant Based on Reference Interaction Site Model Self-Consistent Field with Constrained Spatial Electron Density
The Journal of Physical Chemistry Letters,
Journal Year:
2024,
Volume and Issue:
15(29), P. 7473 - 7481
Published: July 15, 2024
A
method
for
computing
spin–spin
coupling
constants
(SSCCs)
using
the
reference
interaction
site
model
self-consistent
field
with
constrained
spatial
electron
density
(RISM-SCF-cSED)
is
proposed
first
time.
Describing
solvents
integral
equation
theory
allows
us
to
reflect
solvent
effects
at
atomic
resolution
in
SSCCs
while
accounting
thermal
fluctuations
a
low
computational
cost.
Applying
water,
1,1-difluoroethylene,
and
1-methylaminomethylene-2-naphthalenone
revealed
that
shift
was
evaluated
greater
extent
than
continuum
model.
The
origin
of
this
phenomenon
analyzed
terms
physical
mechanisms
underlying
SSCCs.
Language: Английский