Glossary

Short forms used in this book. Each entry points at a page that uses the term.

AKMC

Adaptive kinetic Monte Carlo. Saddle searches supply the rare events, and kinetic Monte Carlo advances the state. See Adaptive kinetic Monte Carlo.

AMS

Amsterdam Modeling Suite. The potential page documents the I/O and library interfaces. See Potential.

BFGS

Broyden-Fletcher-Goldfarb-Shanno. xtsci-optimize supplies the dense inverse-BFGS. LBFGS is the limited-memory form. See Minimization.

CNA

Common-neighbor labels. 0 is fcc (421), 1 is hcp (422), and 2 is other. See [v3.3.0] - 2026-09-15.

CON

Coordinate file extension. Jobs read frames such as reactant.con and write paths such as neb.con. See In-process jobs (no file IPC).

COSMO

Lab-COSMO

Prefix on the metatomic model id lab-cosmo/pet-mad. See Metatomic interface.

CPMD

Car-Parrinello molecular dynamics. With ranks_per_image, one instanton force call spreads beads across CPMD calculator groups. See Tunnelling splittings.

DFT

Density functional theory. The introduction names VASP among these codes. See eOn: long timescale dynamics software.

EAM

Embedded atom method. The vendored aluminum potential is EAM_Al. See Potential.

FIRE

Fast inertial relaxation engine. opt_method = fire selects it, and the schema also offers a FIRE 2.0 variant. See Optimizer.

FPE

Floating-point exception. v2.12 hardens the signal handler and suspends trapping around libtorch calls. See [v2.12.0] - 2026-03-08.

GHA

GitHub Actions. The release workflow and the Windows build run there. See Release workflow.

GPG

GNU Privacy Guard. Maintainers sign release tags with git tag -s. See Release workflow.

GPR

Gaussian process dimer. min_mode_method = gprdimer runs it when that checkout is present. See Saddle search.

IDPP

Image dependent pair potential. It builds an initial band where linear interpolation would overlap atoms. See Nudged elastic band.

INI

Job configuration syntax. Bracketed sections hold the keys for a run. See General simulation parameters.

IRA

Iterative Rotations and Assignments. match_method = ira rigid-rotates and permutes one NEB endpoint onto the other. See Nudged elastic band.

JOTA

Journal of Optimization Theory and Applications. The minimizer page cites the 1999 and 2001 volumes for the Zhang-Deng-Chen and Zhang-Xu secant. See Minimization.

LBFGS

Limited-memory Broyden-Fletcher-Goldfarb-Shanno. The schema names this minimizer lbfgs. See Minimization.

MLIP

Machine-learning potential. Metatomic loads these models. See Metatomic interface.

MPI

Message Passing Interface. Source builds pass -Dwith_mpi=enabled for the MPI potential. See MPI potential.

NEB

Nudged elastic band. Images along a path between a reactant and a product relax under spring forces. See Nudged elastic band.

NLCG

Nonlinear conjugate gradient. xtsci-optimize keeps the conjugacy across outer steps. See Minimization.

OIDC

OpenID Connect. The PyPI publish step authenticates with it. See Release workflow.

ORCA

ORCA quantum chemistry program. eOn has a direct interface. See Potential.

PBC

Periodic boundary conditions. Molecular calculators can refuse a periodic cell, and Matter can wrap positions. See ARTn (Activation-Relaxation Technique nouveau).

PDM

Tracks versions for the documentation build. See Working with the documentation.

PET-MAD

Metatomic model published as lab-cosmo/pet-mad. The name is one model. See Metatomic interface.

QTST

Path-integral quantum transition-state theory. The instanton page writes the rate as PI-QTST. See Tunnelling splittings.

RFO

Banerjee/Baker rational function optimization. [Xtsci] method = rfo selects it. See Minimization.

RMS

Root-mean-square force. convergence_metric = rms uses ||F||_2 / sqrt(3 N_free). The default metric is the plain Euclidean norm. See Minimization.

RPC

Cap’n Proto remote procedure call. Serve mode exposes a potential through the rgpot protocol. See Serve mode.

RPMD

Ring-polymer molecular dynamics. A transmission coefficient turns the PI-QTST rate into this rate. See Tunnelling splittings.

RTDB

NWChem runtime database. The direct calculator skips a reset when the method parameters stay the same. See rgpot integration (three roles).

SCF

Self-consistent field. NWChem keeps this state from one force call to the next. See rgpot integration (three roles).

SIAM

Society for Industrial and Applied Mathematics. The minimizer page cites SIAM J. Numer. Anal. 1986 for the Grippo-Lampariello-Lucidi window. See Minimization.

SIDPP

S-IDPP

Sequential IDPP. The path grows inward from the reactant and from the product. See Nudged elastic band.

SIMD

Single instruction, multiple data. Highway SIMD is an optional subproject. See [v2.13.0] - 2026-04-18.

SOFI

Point-group detection in IRACompare::findSymmetry. See [v2.13.0] - 2026-04-18.

VASP

Vienna Ab-Initio Simulation Program. eOn drives it through a file interface. See Potential.

XTB

Extended tight-binding models, linked through the native Fortran interface. See Potential.

ZBL

Ziegler-Biersack-Littmark screened nuclear repulsion. sidpp_zbl wraps an IDPP path with it. See Potential.