6. ReaxFF Models
6.1. Introduction
The Reactive Force Field (ReaxFF) replaces fixed bond topologies of classical force fields with the concept of bond order to simulate bond breaking/formation of chemical reactions. Originally conceived for hydrocarbons in the gas phase [1], ReaxFF has been extended to a wide range of applications [2].
Danger
Just because a ReaxFF potential is available with the atoms for your intented application, it DOES NOT mean it is transferable if the training set did not include configurations similar to your intented application. For example, there are many potentials with C/H/O/N atoms but not all have the pi-bond parameters trained so a benzene molecule might behave in a completely unphysical manner. You need to consult the original journal article (doi links below) together with the supplementary materials to confirm the transferability of a given ReaxFF potential to your application.
The Potential Energy Surface (PES) is an insanely immense mathematical object. PES of a system with N atoms doesn’t have N points, it has 3N dimensions! The odds are infinitesimal that someone else visited the same tiny slice of subspace you’re interested in and made a Machine-Learning Inter-Atomic-Potential (ML-IAP) or a Reax Force Field (FF) for you already. Stop looking for potentials from somewhere else, except to practice and learn to maybe get close to what you’re doing. For original research there’s no way around having to generate your own DFT and/or experimental data to train a new MLIAP or FF. This is the purpose of FitSNAP-ReaxFF.
ReaxFF in LAMMPS [3] supports three charge equilibration methods to represent the dynamics of electron density:
while fixed partial charges in classical force fields (eg. CHARMM) do not. FitSNAP-ReaxFF enables retraining of legacy ReaxFF QEq potentials for ACKS2 and QTPIE, including optimization of the bond_softness, chi, eta, gamma, bcut_acks2, and gauss_exp parameters.
6.2. ReaxFF functional form
The ReaxFF overall system energy is expressed as the sum:
Details for each term:
Bond order/energy
Lone pair energy
Overcoordination
Undercoordination
Valence Terms (Angle energy, Penalty energy, Three-body conjugation term)
Correction for C2
Triple bond energy correction
Torsion Terms (Torsion rotation barriers, Four body conjugation term)
Hydrogen bond interactions
Nonbonded interactions (van der Waals, Coulomb)
are presented in the Supporting Information of A ReaxFF Reactive Force Field for Molecular Dynamics Simulations of Hydrocarbon Oxidation by Chenoweth, van Duin, Goddard (2008).
6.3. ReaxFF LAMMPS commands
pair_style reaxff (/kk)
fix qeq/reaxff (/kk)
fix acks2/reaxff (/kk)
fix qtpie/reaxff (/kk)
compute reaxff/bonds (/kk)
compute reaxff/species (/kk)
compute reaxff/atom (/kk)
where (/kk) denotes LAMMPS commands available in KOKKOS package.
Note
KOKKOS version of ReaxFF with -k on t 1 -sf kk
is always used by FitSNAP-ReaxFF.
“IMO anyone and everyone should be using the KOKKOS version of ReaxFF. Not only is it more memory robust and will never have these hbondchk errors, it is also faster on CPUs, at least in most cases that I’ve benchmarked, or same speed at the very least.”– Stan Moore (2024/10) on MatSci.org:Lammps hbondchk failed.“I highly suggest using the KOKKOS package for ReaxFF, works in serial for CPUs too.”– Stan Moore (2024/10) on MatSci.org:Segmentation fault: address not mapped to object at address 0xc2cfb87c.“You could also try the KOKKOS version which doesn’t use the safezone, mincap, and minhbonds factors which can bloat the memory if you set them too high.”– Stan Moore (2025/01) on MatSci.org:Possible memory problem with Reaxff when the total atom number increased.
6.4. Fitting ReaxFF parameters
If a ReaxFF potential is not available for your intented application, then you can fit new parameters
with FitSNAP-ReaxFF from DFT training data. FitSNAP-ReaxFF is based on the Covariance Matrix Adaptation Evolution Strategy (CMAES) optimization algorithm as implemented by the pycma python package. CMAES finds a minimum \(x \in \mathbb{R}^n\) of an objective function \(f(x)\). In FitSNAP-ReaxFF, the objective function minimized is the Sum of Squared Errors (SSE) between DFT reference data and predicted energy/forces given current values of parameters to be optimized.
The FitSNAP-ReaxFF workflow is fundamentally different than FitSNAP but relies on the same underlying infrastructure:
- FitSNAP (SNAP/PACE/…)
Two separate phases after scraping data: (i) process_configs() to calculate descriptors and (ii) perform_fit() to solve for optimal coefficients.
- FitSNAP-ReaxFF
One integrated phase: perform_fit() consists of a loop where process_configs() runs in parallel at each step of the fitting algorithm. During this loop, a population of
popsize
candidateparameters
is refined until the CMAES algorithm meets a termination criteria.
You can start a FitSNAP-ReaxFF optimization with a potential file from reaxff/potentials/reaxff-<AUTHOR><YEAR>.ff
(see below for full list bundled with FitSNAP-ReaxFF). You can also start with any other valid ReaxFF potential file (with the exception of eReaxFF and LG dispersion correction), or FIXME: restart from a previously optimized potential.
N2_ReaxFF example
Let’s start with a simple example related to the nitrogen molecule example of INQ, a modern clean-slate C++/CUDA open source (TD)DFT package from LLNL. DFT reference data can also be obtained from Quantum Espresso (QE), Vienna Ab initio Simulation Package (VASP), literature, online databases,…
First, training data is computed using INQ with PBE functional and saved to JSON/N2/N2*.json
:
from fitsnap3lib.parallel_tools import ParallelTools
from fitsnap3lib.io.input import Config
from fitsnap3lib.calculators.inq import INQ
import json
import numpy as np
bond_scan = [{
"Positions":[[-d/2,0.0,0.0], [d/2,0.0,0.0]],
"AtomTypes":['N','N']
} for d in np.arange(0.9,1.51,.05)]
settings = { "CALCULATOR": {
"calculator": "INQ", "energy": 1, "force": 1, "dipole": 1
}}
pt = ParallelTools()
config = Config(pt, settings)
inq = INQ('inq', pt, config)
inq.process_configs(bond_scan)
for i, b in enumerate(bond_scan):
with open(f'JSON/N2/N2_{i}.json', 'w') as json_file:
json.dump({"Dataset": {"Data": b}}, json_file)
Second, a FitSNAP-ReaxFF optimization with input scripts N2_ReaxFF-<CHARGE_FIX>.in
:
[REAXFF]
potential = reaxff-wood2014.ff
parameters = BND.N.N.p_bo1 BND.N.N.p_bo2 BND.N.N.p_bo3 BND.N.N.p_bo4 BND.N.N.p_bo5 BND.N.N.p_bo6
BND.N.N.p_be1 BND.N.N.p_be2
BND.N.N.De_s BND.N.N.De_p BND.N.N.De_pp
BND.N.N.p_ovun1
[CALCULATOR]
calculator = LAMMPSREAXFF
charge_fix = fix 1 all qeq/reaxff 1 0.0 10.0 1.0e-6 reaxff maxiter 500
energy = .5
force = 0
dipole = .5
[SOLVER]
solver = CMAES
popsize = 10
sigma = 0.1
[SCRAPER]
scraper = JSON
[PATH]
dataPath = JSON
[OUTFILE]
potential = reaxff-n2-qeq.ff
[GROUPS]
group_sections = name training_size
group_types = str float
N2-PBE = 1.0
[REAXFF]
potential = reaxff-wood2014.ff
parameters = GEN.bond_softness
ATM.N.chi ATM.N.eta ATM.N.gamma ATM.N.bcut_acks2
BND.N.N.De_s BND.N.N.p_bo1 BND.N.N.p_bo2
BND.N.N.p_be1 BND.N.N.p_be2
# BND.N.N.De_p BND.N.N.p_bo3 BND.N.N.p_bo4
# BND.N.N.De_pp BND.N.N.p_bo5 BND.N.N.p_bo6
# BND.N.N.p_ovun1
[CALCULATOR]
calculator = LAMMPSREAXFF
charge_fix = fix 1 all acks2/reaxff 1 0.0 10.0 1.0e-6 reaxff maxiter 10000
energy = 1
force = 0
dipole = 1
[SOLVER]
solver = CMAES
popsize = 14
sigma = 0.1
[SCRAPER]
scraper = JSON
[PATH]
dataPath = JSON
[OUTFILE]
potential = reaxff-n2-acks2.ff
[GROUPS]
group_sections = name training_size
group_types = str float
N2 = 1.0
[REAXFF]
potential = reaxff-wood2014.ff
#parameters = ATM.N.chi ATM.N.eta ATM.N.gamma ATM.N.bcut_acks2 ATM.N.gauss_exp
parameters = BND.N.N.p_bo1 BND.N.N.p_bo2 BND.N.N.p_bo3 BND.N.N.p_bo4 BND.N.N.p_bo5 BND.N.N.p_bo6
BND.N.N.p_be1 BND.N.N.p_be2
BND.N.N.De_s BND.N.N.De_p BND.N.N.De_pp
BND.N.N.p_ovun1
[CALCULATOR]
calculator = LAMMPSREAXFF
charge_fix = fix 1 all qtpie/reaxff 1 0.0 10.0 1.0e-6 reaxff maxiter 500
energy = 1
force = 0
[SOLVER]
solver = CMAES
popsize = 10
sigma = 0.1
[SCRAPER]
scraper = JSON
[PATH]
dataPath = JSON
[OUTFILE]
potential = reaxff-n2-qtpie.ff
[GROUPS]
group_sections = name training_size
group_types = str float
N2-PBE = 1.0
Third, potential energy computed along the bond scan \(\text{N}\!\equiv\!\text{N}\) by running LAMMPS with potentials
reaxff-wood2014.ff
reaxff-N2_ReaxFF-qeq.ff
reaxff-N2_ReaxFF-acks2.ff
reaxff-N2_ReaxFF-qtpie.ff
is compared to QM training data with matplotlib and saved to N2_ReaxFF.png
:

6.4.1. FitSNAP-ReaxFF input script
Compared to linear and nonlinear models, the input script for ReaxFF models needs:
[REAXFF]
section instead of[BISPECTRUM]
or[ACE]
section
calculator = LAMMPSREAXFF
instead ofLAMMPSSNAP
,LAMMPSPACE
, …
solver = CMAES
instead of eg.SVD
,PYTORCH
, …
[REAXFF]
section
potential
path of initial ReaxFF potential file
parameters
strings separated by spaces with format<BLOCK>.<ATOM_1>...<ATOM_N>.<NAME>
:
GEN.name
for atom parameters
ATM.C.name
for atom parameters
BND.C.H.name
for bond parameters
OFD.C.H.name
for off-diagonal parameters
ANG.C.H.O.name
for angle parameters
TOR.C.H.O.N.name
for torsion parameters
HBD.C.H.O.name
for hydrogen-bond parameterswhere
name
is LAMMPS implementation parameter name (which might be different than other ReaxFF implementations commonly seen in comments of potential files)
Block | Position | Name | Description | Category | Eq. [15] |
---|---|---|---|---|---|
GEN | R1 | p_boc1 | Overcoordination parameter | Expert | 4c |
GEN | R2 | p_boc2 | Overcoordination parameter | Expert | 4d |
GEN | R3 | p_coa2 | Valency angle conjugation parameter | Expert | 15 |
GEN | R4 | p_trip4 | Triple bond stabilization parameter | Expert | 20 |
GEN | R5 | p_trip3 | Triple bond stabilization parameter | Expert | 20 |
GEN | R6 | k_c2 | C2-correction | Expert | 19 |
GEN | R7 | p_ovun6 | Undercoordination parameter | Expert | 12 |
GEN | R8 | p_trip2 | Triple bond stabilization parameter | Expert | 20 |
GEN | R9 | p_ovun7 | Undercoordination parameter | Expert | 12 |
GEN | R10 | p_ovun8 | Undercoordination parameter | Expert | 12 |
GEN | R11 | p_trip1 | Triple bond stabilization energy | Expert | 20 |
GEN | R12 | nonb_low,swa | Lower Taper-radius | DoNotOptimize | 21 |
GEN | R13 | R_cut | Upper Taper-radius | DoNotOptimize | 21 |
GEN | R14 | p_fe1 | Fe dimer correction | DoNotOptimize | 6a |
GEN | R15 | p_val6 | Valency undercoordination | Expert | 13c |
GEN | R16 | p_lp1 | Valency angle/lone pair parameter | Expert | 8 |
GEN | R17 | p_val9 | Valency angle parameter | Expert | 13f |
GEN | R18 | p_val10 | Valency angle parameter | Expert | 13g |
GEN | R19 | p_fe2 | Fe dimer correction | DoNotOptimize | 6a |
GEN | R20 | p_pen2 | Double bond/angle parameter | Expert | 14a |
GEN | R21 | p_pen3 | Double bond/angle parameter: overcoord | Expert | 14b |
GEN | R22 | p_pen4 | Double bond/angle parameter: overcoord | Expert | 14b |
GEN | R23 | p_fe3 | Fe dimer correction | DoNotOptimize | 6a |
GEN | R24 | p_tor2 | Torsion/BO parameter | Expert | 16b |
GEN | R25 | p_tor3 | Torsion overcoordination | Expert | 16c |
GEN | R26 | p_tor4 | Torsion overcoordination | Expert | 16c |
GEN | R28 | p_cot2 | Conjugation | Expert | 17b |
GEN | R29 | p_vdW1 | VdW shielding | Expert | 23b |
GEN | R30 | cutoff*100 | Cutoff for bond order (* 100) | Expert | 3a,b |
GEN | R31 | p_coa4 | Valency angle conjugation parameter | Expert | 15 |
GEN | R32 | p_ovun4 | Overcoordination parameter | Expert | 11b |
GEN | R33 | p_ovun3 | Overcoordination parameter | Expert | 11b |
GEN | R34 | p_val8 | Valency/lone pair parameter | Expert | 13d |
GEN | R35 | X_soft | ACKS2 softness parameter | Expert | 25 |
GEN | R39 | p_coa3 | Valency angle conjugation parameter | Expert | 15 |
ATM | R1C1 | r_s | σ-bond covalent radius | Standard | 2 |
ATM | R1C2 | valency | Valency | DoNotOptimize | 3a,4b,5,9a |
ATM | R1C3 | mass | Atomic mass | DoNotOptimize | 9a |
ATM | R1C4 | r_vdw | van der Waals radius | Expert | 23a |
ATM | R1C5 | epsilon | van der Waals dissociation energy | Expert | 23a |
ATM | R1C6 | gamma | Valence orbital exponent (QEQ, ACKS2, QTPIE) | Expert | 24 |
ATM | R1C7 | r_pi | π-bond covalent radius | Standard | 2 |
ATM | R1C8 | valency_e | Number of valence electrons | DoNotOptimize | 7,8,9 |
ATM | R2C1 | alpha | van der Waals parameter | Expert | 23b |
ATM | R2C2 | gamma_w | van der Waals shielding | Expert | 23b |
ATM | R2C3 | valency_boc | Valency for 1, 3-BO correction | DoNotOptimize | 16c,13c |
ATM | R2C4 | p_ovun5 | Undercoordination energy | Expert | 12 |
ATM | R2C5 | gauss_exp | Gaussian orbital exponent (QTPIE) | Expert | 26 |
ATM | R2C6 | chi | Electronegativity [always eV] (QEQ, ACKS2, QTPIE) | Expert | 24,25 |
ATM | R2C7 | eta | Atomic hardness [always eV] (QEQ, ACKS2, QTPIE) | Expert | 24,25 |
ATM | R2C8 | p_hbond | Donor or acceptor switch in H-bonds | DoNotOptimize | n/a |
ATM | R3C1 | r_pi_pi | π-π-bond covalent radius | Standard | 2 |
ATM | R3C2 | p_lp2 | Lone pair energy | Expert | 10 |
ATM | R3C3 | n/a | Atomic heat of formation | DoNotOptimize | n/a |
ATM | R3C4 | b_o_131 | Bond order correction | Expert | 4e,f |
ATM | R3C5 | b_o_132 | Bond order correction | Expert | 4e,f |
ATM | R3C6 | b_o_133 | Bond order correction | Expert | 4e,f |
ATM | R3C7 | bcut_acks2 | Atomic softness cutoff parameter (ACKS2) | Expert | 25 |
ATM | R4C1 | p_ovun2 | Valence angle parameter | Expert | 12 |
ATM | R4C2 | p_val3 | Valence angle parameter | Expert | 13b,13a |
ATM | R4C4 | valency_val | Number of lone pairs | DoNotOptimize | 3b |
ATM | R4C5 | p_val5 | Valence angle parameter | Expert | 13b |
ATM | R4C6 | rcore2 | Inner wall vdW repulsion parameter | Expert | 23c |
ATM | R4C7 | ecore2 | Inner wall vdW repulsion parameter | Expert | 23c |
ATM | R4C8 | acore2 | Inner wall vdW repulsion parameter | Expert | 23c |
BND | R1C1 | De_s | σ-bond dissociation energy | Standard | 6,11a |
BND | R1C2 | De_p | π-bond dissociation energy | Standard | 6 |
BND | R1C3 | De_pp | π-π-bond dissociation energy | Standard | 6 |
BND | R1C4 | p_be1 | Bond energy parameter coefficient | Standard | 6 |
BND | R1C5 | p_bo5 | π-π-bond parameter coefficient | Standard | 2 |
BND | R1C6 | v13cor | 1,3-Bond order correction | DoNotOptimize | 3b |
BND | R1C7 | p_bo6 | π-π-bond order exponent | Standard | 2 |
BND | R1C8 | p_ovun1 | Overcoordination penalty | Standard | 11a |
BND | R2C1 | p_be2 | Bond energy parameter exponent | Standard | 6 |
BND | R2C2 | p_bo3 | π-bond order parameter coefficient | Standard | 2 |
BND | R2C3 | p_bo4 | π-bond order parameter exponent | Standard | 2 |
BND | R2C5 | p_bo1 | σ-bond order coefficient | Standard | 2 |
BND | R2C6 | p_bo2 | σ-bond order exponent | Standard | 2 |
BND | R2C7 | ovc | Uncorrected BO overcoordination | DoNotOptimize | 3a |
OFD | R1C1 | D | VdW energy | Expert | 23a |
OFD | R1C2 | r_vdW | VdW radius | Expert | 23a |
OFD | R1C3 | alpha | VdW parameter | Expert | 23a |
OFD | R1C4 | r_s | σ-bond length | Standard | 2 |
OFD | R1C5 | r_p | π-bond length | Standard | 2 |
OFD | R1C6 | r_pp | π-π-bond length | Standard | 2 |
ANG | R1C1 | theta_00 | 180o-(equilibrium angle) | Standard | 13g |
ANG | R1C2 | p_val1 | Valence angle parameter | Standard | 13a |
ANG | R1C3 | p_val2 | Valence angle parameter | Standard | 13a |
ANG | R1C4 | p_coa1 | Valence conjugation | Expert | 15 |
ANG | R1C5 | p_val7 | Undercoordination | Expert | 13c |
ANG | R1C6 | p_pen1 | Penalty energy | Expert | 14b,14a |
ANG | R1C7 | p_val4 | Valence angle parameter | Expert | 13b |
TOR | R1C1 | V1 | V1-torsion barrier | Standard | 16a |
TOR | R1C2 | V2 | V2-torsion barrier | Standard | 16a |
TOR | R1C3 | V3 | V3-torsion barrier | Standard | 16a |
TOR | R1C4 | p_tor1 | Torsion angle parameter | Standard | 16a |
TOR | R1C5 | p_cot1 | Conjugation energy | Expert | 17a |
HBD | R1C1 | r0_hb | Hydrogen bond equilibrium distance | Standard | 18 |
HBD | R1C2 | p_hb1 | Hydrogen bond energy | Standard | 18 |
HBD | R1C3 | p_hb2 | Hydrogen bond/bond order | Expert | 18 |
HBD | R1C4 | p_hb3 | Hydrogen bond parameter | Expert | 18 |
Note
reaxff/tools/reaxff-format-ff.py
properly reformats a ReaxFF potential file (eg. copy/pasted from journal articles) together with LAMMPS implementation parameter names in comment fields.
[CALCULATOR]
section
calculator
must beLAMMPSREAXFF
for FitSNAP-ReaxFF
charge_fix
charge equilibration fix command, eg:
(a)
fix 1 all qeq/reaxff 1 0.0 10.0 1.0e-6 reaxff
(b)
fix 1 all acks2/reaxff 1 0.0 10.0 1.0e-6 reaxff maxiter 500
(c)
fix 1 all qtpie/reaxff 1 0.0 10.0 1.0e-6 reaxff exp.qtpie
fix ID (
1
in examples a-c), can only contain alphanumeric characters and underscores to be valid in LAMMPS
energy
turn on1
or off0
energy fitting
force
turn on1
or off0
force fitting
stress
ignored in FitSNAP-ReaxFF
dipole
turn on1
or off0
dipole fitting
Note
Stress fitting is not supported in FitSNAP-ReaxFF, only energy = 1
and force = 1
are available.
[SOLVER]
section
solver
must beCMAES
for FitSNAP-ReaxFF
popsize
population size setting of CMAES algorithm, with default \(4+3*log(|P|)\) where \(|P|\) is the number of parameters to be optimized. [detailed discussion with the author of the pycma python package]
sigma
sigma setting of CMAES algorithm, with default 0.1
[SCRAPER]
section
same as FitSNAP
[PATH]
section
same as FitSNAP
[OUTFILE]
section
potential
path of optimized ReaxFF potential file
output_style
not applicable becauseoutput_style=REAXFF
implied by REAXFF section
[REFERENCE]
section
not applicable in FitSNAP-ReaxFF
Note
FitSNAP-ReaxFF only supports units real
and atom_style charge
.
[GROUPS]
section
same as FitSNAP
6.5. Available ReaxFF potentials
Branch |
Atoms |
Filename |
Source |
---|---|---|---|
combustion |
C / H |
n/a |
van Duin et al.[1] |
6.5.1. Combustion Branch
Branch |
Atoms |
Filename (LAMMPS) |
Source |
|
---|---|---|---|---|
combustion |
Au/S/C/H |
reaxff-jarvi2011.ff |
AuSCH_2011.ff |
Järvi et al.[9] |
combustion |
C |
reaxff-srinivasan2015.ff |
C.ff |
Srinivasan et al.[10] |
combustion |
C/H |
reaxff-mao2017.ff |
CH_aromatics.ff |
Mao et al.[11] |
combustion |
C/H/B/N |
reaxff-pai2016.ff |
CBN.ff |
Pai et al.[12] |
combustion |
C/H/Na |
reaxff-hjertenaes2016.ff |
CHNa.ff |
Hjertenæs et al.[13] |
combustion |
C/H/O |
reaxff-ashraf2017.ff |
CHO-2016.ff |
Ashraf and Van Duin[14] |
combustion |
C/H/O |
reaxff-chenoweth2008a.ff |
CHO.ff |
Chenoweth et al.[15] |
combustion |
C/H/O/Ba/Zr/Y |
reaxff-vanduin2008.ff |
BaYZrCHO.ff |
Van Duin et al.[16] |
combustion |
C/H/O/N |
reaxff-strachan2003.ff |
n/a |
Strachan et al.[17] |
FIXME |
C/H/O/N |
reaxff-budzien2009.ff |
n/a |
Budzien et al.[18] |
FIXME |
C/H/O/N/S |
reaxff-mattsson2010.ff |
n/a |
Mattsson et al.[19] |
FIXME |
C/H/O/N/S/F/Pt/Cl/Ni/X |
reaxff-singh2013.ff |
n/a |
Singh et al.[20] |
combustion |
C/H/O/N/S/Si |
reaxff-liu2011.ff |
dispersion/CHONSSi-lg.ff |
Liu et al.[21] |
combustion |
C/H/O/N/S/Si |
reaxff-zhang2009.ff |
HE2.ff |
Zhang et al.[22] |
combustion |
C/H/O/N/S/Si/Ge |
reaxff-psofogiannakis2016.ff |
CHONSSiGe.ff |
Psofogiannakis and Van Duin[23] |
combustion |
C/H/O/N/S/Si/Na/P |
reaxff-zhang2014.ff |
CHONSSiNaP.ff |
Zhang et al.[24] |
combustion |
C/H/O/N/S/Si/Pt/Zr/Ni/Cu/Co |
reaxff-nielson2005.ff |
CHONSSiPtZrNiCuCo.ff |
Nielson et al.[25] |
combustion |
C/H/O/N/S/Si/Pt/Ni/Cu/Co/Zr/Y/Ba |
reaxff-merinov2014.ff |
CHONSSiPtNiCuCoZrYBa.ff |
Merinov et al.[26] |
combustion |
C/H/O/N/S/Si/Pt/Zr/Ni/
Cu/Co/He/Ne/Ar/Kr/Xe
|
reaxff-kamat2010.ff |
CHONSSiPtZrNiCuCoHeNeArKrXe.ff |
Kamat et al.[27] |
combustion |
C/H/O/N/Si/S |
reaxff-kulkarni2013.ff |
SiONH.ff |
Kulkarni et al.[28] |
combustion |
C/H/O/S |
reaxff-mueller2016.ff |
Mue2016.ff |
Müller and Hartke[29] |
combustion |
C/H/O/S |
reaxff-komissarov2021.ff |
n/a |
Komissarov et al.[30] |
combustion |
C/H/O/S/F/Cl/N |
reaxff-wood2014.ff |
CHOSFClN.ff |
Wood et al.[31] |
combustion |
C/H/Pt |
reaxff-sanz2008.ff |
PtCH.ff |
Sanz-Navarro et al.[32] |
combustion |
C/H/O/Si |
reaxff-chenoweth2005.ff |
PDMSDecomp.ff |
Chenoweth et al.[33] |
FIXME |
H/O/Au |
reaxff-joshi2010.ff |
n/a |
Joshi et al.[34] |
combustion |
Co |
reaxff-zhang2014b.ff |
Co.ff |
Zhang et al.[35] |
combustion |
H/O/N/B |
reaxff-weismiller2010.ff |
Ab.ff |
Weismiller et al.[36] |
combustion |
Li/S |
reaxff-islam2015.ff |
LiS.ff |
Islam et al.[37] |
combustion |
Ni/C/H |
reaxff-mueller2010.ff |
NiCH.ff |
Mueller et al.[38] |
combustion |
O/Pt |
reaxff-fantauzzi2014.ff |
OPt.ff |
Fantauzzi et al.[39] |
combustion |
Pd/H |
reaxff-senftle2014.ff |
PdH.ff |
Senftle et al.[40] |
combustion |
Si/C/O/H/N/S |
reaxff-newsome2012.ff |
SiC.ff |
Newsome et al.[41] |
combustion |
V/O/C/H |
reaxff-chenoweth2008b.ff |
VOCH.ff |
Chenoweth et al.[42] |
6.5.2. Independent Branch
Branch |
Atoms |
Filename (LAMMPS) |
Source |
|
---|---|---|---|---|
independent |
C/H/Ar/He/Ne/Kr |
reaxff-yoon2016.ff |
CHArHeNeKr.ff |
Yoon et al.[43] |
independent |
C/H/Fe |
reaxff-islam2016.ff |
CHFe.ff |
Islam et al.[44] |
independent |
C/H/Ga
C/H/In
|
reaxff-rajabpour2021a.ff
reaxff-rajabpour2021b.ff
|
GaCH-2020.ff
InCH-2020.ff
|
Rajabpour et al.[45] |
independent |
C/H/O/Ge |
reaxff-nayir2018.ff |
CHOGe.ff |
Nayir et al.[46] |
independent |
C/H/O/Li/Al/Ti/P |
reaxff-shin2018.ff |
CHOLiAlTiP.ff |
Shin et al.[47] |
independent |
C/H/O/N/B/Al/Si/Cl |
reaxff-uene2024.ff |
CHONBAlSiCl.ff |
Uene et al.[48] |
independent |
C/H/O/N/S/Mg/P/Na/Cu/Cl/Ti/X |
reaxff-hou2022.ff |
CHONSMgPNaCuClTi.ff |
Hou et al.[49] |
independent |
C/H/O/N/S/Si |
reaxff-soria2018.ff |
CHONSSi.ff |
Soria et al.[50] |
independent |
C/H/O/N/S/Si/Ge/Ga/Ag |
reaxff-niefind2024.ff |
CHONSSiGeGaAg.ff |
Niefind et al.[51] |
independent |
C/H/O/N/S/Zr |
reaxff-dwivedi2020.ff |
CHONSZr.ff |
Dwivedi et al.[52] |
independent |
C/H/O/N/Si |
reaxff-wang2020.ff |
CHONSi.ff |
Wang et al.[53] |
independent |
C/H/O/S/Cu/Cl/X |
reaxff-yeon2018.ff |
CuSCH.ff |
Yeon et al.[54] |
independent |
C/H/O/S/Mo/Ni/Au/Ti |
reaxff-mao2022.ff |
CHOSMoNiAuTi.ff |
Mao et al.[55] |
independent |
Cu/Zr |
reaxff-huang2019.ff |
CuZr.ff |
Huang et al.[56] |
independent |
H/O/N/Si/F |
reaxff-kim2021.ff |
HONSiF.ff |
Kim et al.[57] |
independent |
H/O/Si/Al/Li |
reaxff-ostadhossein2016.ff |
HOSiAlLi.ff |
Ostadhossein et al.[58] |
independent |
H/S/Mo |
reaxff-ostadhossein2017.ff |
HSMo.ff |
Ostadhossein et al.[59] |
independent |
I/Br/Pb/Cs |
reaxff-pols2024.ff |
IBrPbCs.ff |
Pols et al.[60] |
independent |
I/Pb/Cs/X |
reaxff-pols2021.ff |
CsPbI.ff |
Pols et al.[61] |
independent |
Li/Si/C |
reaxff-olou2023.ff |
LiSiC.ff |
Olou’ou Guifo et al.[62] |
independent |
Mg/O |
reaxff-fiesinger2023.ff |
MgO.ff |
Fiesinger et al.[63] |
independent |
Ni/Al |
reaxff-du2023.ff |
NiAl.ff |
Du et al.[64] |
independent |
Ni/Cr |
reaxff-shin2021.ff |
NiCr.ff |
Shin et al.[65] |
independent |
Ru/H |
reaxff-onwudinanti2022.ff |
RuH.ff |
Onwudinanti et al.[66] |
independent |
Ru/N/H |
reaxff-kim2018.ff |
RuNH.ff |
Kim et al.[67] |
independent |
Si/Al/Mg/O |
reaxff-yeon2021.ff |
SiAlMgO.ff |
Yeon et al.[68] |
independent |
Si/O/H |
reaxff-nayir2019.ff |
SiOHv2.ff |
Nayir et al.[69] |
independent |
W/S/H/Al/O |
reaxff-nayir2021.ff |
WSHAlO.ff |
Nayir et al.[70] |
independent |
Zr/Y/O/H |
reaxff-mayernick2010.ff |
ZrYOHVac.ff |
Mayernick et al.[71] |
independent |
Zr/Y/O/Ni/H |
reaxff-liu2019.ff |
ZrYONiH.ff |
Liu et al.[72] |
6.5.3. Water Branch
Branch |
Atoms |
Filename (LAMMPS) |
Source |
|
---|---|---|---|---|
water |
Al/C/H/O |
reaxff-hong2016.ff |
AlCHO.ff |
Hong and Van Duin[73] |
water |
C/H/O/Al/Ge/X |
reaxff-zheng2017.ff |
CHOAlGeX.ff |
Zheng et al.[74] |
water |
C/H/O/Ca/Si/X |
reaxff-manzano2012.ff |
CaSiOH.ff |
Manzano et al.[75] |
water |
C/H/O/Cs/K/Na/Cl/I/F/Li |
reaxff-fedkin2019.ff |
CHOCsKNaClIFLi.ff |
Fedkin et al.[76] |
water |
C/H/O/Fe |
reaxff-aryanpour2010.ff |
FeOCHCl.ff |
Aryanpour et al.[77] |
water |
C/H/O/Fe/Al/Ni/Cu/S/Cr |
reaxff-shin2015.ff |
CHOFeAlNiCuSCr.ff |
Shin et al.[78] |
water |
C/H/O/Fe/Al/Ni/Cu/S/Cr |
reaxff-tavazza2015.ff |
CHOFeAlNiCuSCr_v3.ff |
Tavazza et al.[79] |
water |
C/H/O/N |
reaxff-rahaman2011.ff |
Glycine.ff |
Rahaman et al.[80] |
water |
C/H/O/N |
reaxff-trnka2018.ff |
n/a |
Trnka et al.[81] |
water |
C/H/O/N |
reaxff-kowalik2019.ff |
CHON-2019.ff |
Kowalik et al.[82] |
water |
C/H/O/N/S/Fe |
reaxff-moerman2021.ff |
CHONSFe.ff |
Moerman et al.[83] |
water |
C/H/O/N/S/Mg/P/Na/Cu |
reaxff-huang2013.ff |
CuBTC.ff |
Huang et al.[84] |
water |
C/H/O/N/S/Mg/P/Na/Cu/Cl |
reaxff-monti2013a.ff |
CHONSMgPNaCuCl.ff |
Monti et al.[85] |
water |
C/H/O/N/S/Mg/P/Na/Cu/Cl |
reaxff-monti2013b.ff |
CHONSMgPNaCuCl_v2.ff |
Monti et al.[86] |
water |
C/H/O/N/S/Mg/P/Na/Cu/Cl/X |
reaxff-zhang2018.ff |
CHON2017_weak.ff |
Zhang and Van Duin[87] |
water |
C/H/O/N/S/Mg/P/Na/Ti/Cl/F |
reaxff-huygh2014.ff |
CHONSMgPNaTiClF.ff |
Huygh et al.[88] |
water |
C/H/O/N/S/Mg/P/Na/Ti/Cl/F |
reaxff-kim2013a.ff |
TiOCHNCl.ff |
Kim et al.[89] |
water |
C/H/O/N/S/Mg/P/Na/Ti/Cl/F |
reaxff-kim2013b.ff |
TiClOH.ff |
Kim and van Duin[90] |
water |
C/H/O/N/S/Mg/P/Na/Ti/Cl/F/Au |
reaxff-monti2016.ff |
CHONSMgPNaTiClFAu.ff |
Monti et al.[91] |
water |
C/H/O/N/S/Mg/P/Na/Ti/Cl/F/K/Li |
reaxff-ganeshan2020.ff |
CHONSMgPNaTiClFKLi.ff |
Ganeshan et al.[92] |
water |
C/H/O/N/Si/Cu/Ag/Zn |
reaxff-lloyd2016.ff |
AgZnO.ff |
Lloyd et al.[93] |
water |
C/H/O/N/S/Si/Ca/Cs/K/Sr/Na/Mg/Al/Cu |
reaxff-psofogiannakis2015.ff |
CHONSSiCaCsKSrNaMgAlCu.ff |
Psofogiannakis et al.[94] |
water |
C/H/O/N/S/Si/Na/Al |
reaxff-bai2012.ff |
CHONSSiNaAl.ff |
Bai et al.[95] |
water |
C/H/O/S/Mo/Ni/Li/B/F/P/N |
reaxff-liu2021.ff |
CHOSMoNiLiBFPN-2.ff |
Liu et al.[96] |
water |
C/H/O/Si/Na |
reaxff-hahn2018.ff |
CHOSiNa.ff |
Hahn et al.[97] |
water |
C/H/O/Zn |
reaxff-han2010.ff |
CHOZn.ff |
Han et al.[98] |
water |
H/O/Si/Al/Li |
reaxff-narayanan2011.ff |
SiOAlLi.ff |
Narayanan et al.[99] |
water |
H/O/X |
reaxff-zhang2017.ff |
Water2017.ff |
Zhang and Van Duin[100] |
water |
Zn/O/H |
reaxff-raymand2010.ff |
ZnOH.ff |
Raymand et al.[101] |