AMBER (Assisted Model Building with Energy Refinement)

Biomolecular simulation suite and foundational family of empirical force fields for proteins, nucleic acids, and small molecules.

Specifications & Metrics

type: Biomolecular Force Fields & MD Suite
language: Fortran, C, C++, CUDA
license: Open-source AmberTools (GPL/LGPL) with licensed pmemd high-performance engine
developer: Originated by Paul Weiner and Peter Kollman at UCSF (released 1981); maintained by David A. Case and the AMBER consortium

Originally written by Paul Weiner in Peter Kollman's laboratory at UCSF and released in 1981, AMBER designates both a suite of molecular dynamics programs (sander, pmemd) and the widely adopted AMBER biomolecular force fields.
The General AMBER Force Field (GAFF) and the Antechamber toolkit parameterize arbitrary drug-like organic molecules with RESP/AM1-BCC partial charges so ligands can be simulated seamlessly alongside ff14SB/ff19SB protein models.
AMBER pioneered thermodynamic integration (TI), MM-PBSA / MM-GBSA end-point binding free-energy calculations, and GPU-accelerated alchemical free-energy methods used to rank congeneric series in lead optimization.